Curable compositions

ABSTRACT

The present invention has for its object to provide a curable composition which, despite its low viscosity, gives a cured product with a high gel fraction, low residual tack, low modulus, high elongation, and good flexibility. 
     The present invention relates to a curable composition comprising the following two components:
     (A) a vinyl polymer having at least one crosslinking silyl group on the average per molecule: and   (B) a photocurable substance, (C) an air oxidation-curable substance, (D) a high molecular plasticizer, (E) a reactive plasticizer or (F) a compound having one silanol group in its molecule and/or a compound capable of reacting with moisture to give a compound having one silanol group in the molecule.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.09/807,038, filed Jul. 23, 2001, now abandoned, which in turn was theU.S. national stage of PCT/JP99/05557, filed Oct. 8, 1999.

TECHNICAL FIELD

The present invention relates to a curable composition. Moreparticularly, the invention relates to a curable composition comprisinga vinyl polymer having a crosslinking functional group such as acrosslinking silyl group.

BACKGROUND ART

Referring to vinyl polymers produced by radical polymerization, incontrast to those polymers which are produced by ionic polymerization orpolycondensation, few polymers having functional groups, particularlyvinyl polymers at molecular chain terminus such functional groups, areavailable as of today. Among such vinyl polymers, (meth)acrylic polymershave certain characteristics not shared by polyether polymers,hydrocarbon polymers or polyester polymers, such as high weatheringresistance and transparency, and said (meth)acrylic polymers having analkenyl or crosslinking silyl group in the side chain have been utilizedin weather-resistant coatings, among other applications. Meanwhile, thecontrol of polymerization reaction of acrylic polymers is handicapped byside reactions and the introduction of a functional group into themolecular chain terminus, for instance, is extremely difficult.

Should it be possible to produce an alkenyl group-terminated vinylpolymer by an expedient method, cured products having superior physicalproperties as compared with those obtainable from ones havingcrosslinking side-chain groups could be obtained. From this point ofview, attempts to establish such a technology have been made by many,workers to this day but actually it has proved difficult to produce suchpolymers on a commercial scale. By way of illustration, Japanese KokaiPublication Hei-1-247403 and Japanese Kokai Publication Hei-5-255415disclose processes for synthesizing alkenyl-terminated (meth)acrylicpolymers using an alkenyl group-containing disulfide as the chaintransfer agent.

Japanese Kokai Publication Hei-5-262808 discloses a process forproducing an alkenyl-terminated (meth)acrylic polymer which comprisessynthesizing a vinyl polymer having a hydroxyl group at both termini byusing a hydroxyl-containing disulfide and, then, converting the terminalhydroxyl group to an alkenyl group by utilizing the reactivity of thehydroxyl functional group.

Japanese Kokai Publication Hei-5-211922 discloses a process forproducing a silyl-terminated (meth)acrylic polymer which comprisessynthesizing a vinyl polymer having a hydroxyl group at both termini byusing a hydroxyl-containing polysulfide and converting the terminalhydroxyl groups to silyl groups by utilizing the reactivity of thehydroxyl functional group.

By these processes, however, it is difficult to certainly introducefunctional groups into both termini of the molecular chain, hence togive cured products having satisfactory characteristics. In order that afunctional group may be introduced into both termini with certainty, thechain transfer agent must be used in a large amount, which isdisadvantageous process-wise. Furthermore, since the reaction involves astandard radical polymerization reaction in these processes, themolecular weight and molecular weight distribution (the ratio of weightaverage molecular weight to number average molecular weight) of theproduct polymer cannot be easily controlled.

In view of the above conventional technology, the inventors already didseveral inventions relating to vinyl polymers having variouscrosslinking silyl groups at its terminus, processes for producing thepolymers, curable compositions and uses [e.g. Japanese Kokai PublicationHei-11-080249, Japanese Kokai Publication Hei-11-080250, Japanese KokaiPublication Hei-11-005815, Japanese Kokai Publication Hei-11-116617,Japanese Kokai Publication Hei-11-116606, Japanese Kokai PublicationHei-11-080571, Japanese Kokai Publication Hei-11-080570, Japanese KokaiPublication Hei-11-130931, Japanese Kokai Publication Hei-11-100433,Japanese Kokai Publication Hei-11-116763, Japanese Kokai PublicationHei-9-272714, Japanese Kokai Publication Hei-9-272715, etc.]

For example, a vinyl polymer having a crosslinking silicon-containinggroup (hereinafter referred to sometimes as “crosslinking silyl group”)comprising a hydroxyl or hydrolyzable group bound to a silicon atom andcapable of siloxane bonding or a cured product obtainable from this hasexcellent heat resistance and weather resistance, therefore these can beused in various fields such as architectural elastic sealants andcomposite-glass sealants, coatings, sealing materials or members and soon.

However, cured products available from such a vinyl polymer having acrosslinking silyl group tend to have the drawback of a conflict betweenhardness and surface tackiness (also referred as to tacky or residualtack); that is to say, products which is required to be low hardness,i.e. elastic, express a greater residual tack on its surface and tend tobe easily soiled. For example, in use as an architectural sealant, theresidual tack attracts soil and dust to the surface to adversely affectthe appearance of buildings. The first aspect of the present invention,therefore, has for its object to reduce the surface tackiness (residualtack) of cured products obtainable from vinyl polymer having acrosslinking silyl group.

Meanwhile, cured products obtainable by using a vinyl polymer having acrosslinking functional group such as a crosslinking silyl group as thecurable component have satisfactory heat resistance and weatherresistance and exhibit good coatability when a coating is appliedthereon. However, when a well-known plasticizer of comparatively lowmolecular weight, such as a phthalic acid ester, is used for the purposeof lowering the viscosity of the formulation, the gradual elution of theplasticizer by heat or rain water from the cured product makes itdifficult to maintain the initial physical properties of the product fora long time. The additional disadvantage is that when a coating known as“alkyd coating” is applied, the coating is hard to be dried and cureeasily.

Therefore, the second aspect of the present invention has for its objectto reduce the surface tackiness (residual tack) of the cured productobtainable by using a vinyl polymer having a crosslinking silyl group asthe curable component to thereby minimize the settlement of dust thereonwhile upholding the satisfactory mechanical properties of the curedproduct and, at the same time, improve the coatability of the product,to an alkyd coating. The third aspect of the present invention has forits object to maintain the heat resistance and weather resistance of thecured product available from the crosslinking functionalgroup-containing vinyl polymer over a protracted time period and, at thesame time, improve the coatablilty of the cured product to an alkydcoating.

Meanwhile, in order to impart flexibility to such cured products throughreduction in the modulus thereof, it is generally necessary to increasethe molecular weight of the polymer but this entails an increasedviscosity of the polymer, thus detracting from workability. Analternative approach comprises lowering the rate of introduction of acrosslinking silyl group instead of increasing the molecular mass of thepolymer but, in this case, the uncrosslinked fraction is increased tocause a reduced cure speed and a reduced gel fraction of the curedproduct, thus exerting adverse effects on physical properties other thanflexibility. Therefore, in order to reduce viscosity while sustainingflexibility, it is common practice to add one of various plasticizers.

As such plasticizers, there can be mentioned aromatic carboxylic acidesters, aliphatic carboxylic acid esters, phosphoric acid esters,glycols, epoxy plasticizers and chlorinated paraffin, among others.However, these plasticizers have migrating properties so that when usedfor sealants or adhesives, they tend to cause such troubles as foulingat and around sealed joints, adverse influences on adhesion, and adecrease in flexibility due to extraction of the plasticizer onprolonged curing. The fourth aspect of the present invention, therefore,has for its object to improve workability in a compounding stage or acurable composition application stage, to impart flexibility to curedproducts, and inhibit adverse influences of plasticizer migration.

As means for reducing the crosslinking silyl group content of a vinylpolymer without reducing the amount of introduction of the crosslinkingsilyl group to thereby impart flexibility to cured products through areduction in modules, Japanese Kokai Publication Sho-61-34067 andJapanese Kokai Publication Sho-64-9268, among others, disclose thetechnology involving addition of a compound having one silanol group permolecule and/or a compound capable of reacting with moisture to give acompound containing one silanol group per molecule (hereinaftersometimes these are collectively referred to as “silanol-containingcompound”).

However, the organic vinyl polymer containing at least one reactivesilicon functional group per molecule as described in Japanese KokaiPublication Sho-61-34067 is produced by the standard free radicalpolymerization reaction using a chain transfer agent and, therefore, hasa high viscosity as well as the disadvantage that in order to attainflexibility while retaining a high gel fraction, it is necessary to usean unsaturated organosilicon monomer in a large amount and asilanol-containing compound also in an increased amount. The fifthaspect of the present invention, therefore, has for its object toprovide a curable composition which, despite its low viscosity, gives acured product with a high gel fraction, low residual tack, low modulus,high elongation, and good flexibility.

SUMMARY OF THE INVENTION

The first aspect of the present invention is directed to a curablecomposition comprising the following two components:

-   (A1) a vinyl polymer having at least one crosslinking silyl group of    the general formula (1) on the average per molecule:    —[Si(R¹)_(2-b)(Y)_(b)O]_(m)—Si(R²)_(3-a)(Y)_(a)  (1)    wherein R¹ and R² maybe the same or different and each represents an    alkyl group containing 1 to 20 carbon atoms, an aryl group    containing 6 to 20 carbon atoms, an aralkyl group containing 7 to 20    carbon atoms, or a triorganosiloxy group of the formula (R′)₃SiO—,    where R′ represents a univalent hydrocarbon group containing 1 to 20    carbon atoms and the plurality of R′ groups maybe the same or    different, and when two or more R¹ or R² groups are present, they    may be the same or different; Y represents a hydroxyl group or a    hydrolyzable group and, when two or more Y groups are respectively    present, they may be the same or different; a represents an integer    of 0, 1, 2 or 3; b represents an integer of 0, 1 or 2; m is an    integer of 0 to 19; with the condition that the relation of a+mb≧1    is satisfied and-   (B) a photocurable substance.

The second aspect of the present invention is directed to a curablecomposition comprising

-   (A2) a vinyl polymer having at least one crosslinking silyl group of    the above general formula (1) on the average per molecule and-   (C) an air oxidation-curable substance.

The third aspect of the present invention is directed to a curablecomposition comprising

-   (A3) a vinyl polymer having at least one crosslinking functional    group on the average and-   (D) a high molecular plasticizer.

The fourth aspect of the present invention is directed to a curablecomposition comprising

-   (A4) a vinyl polymer having not less than 1.1 of crosslinking silyl    groups of the above general formula (1) on the average per molecule    and-   (E) a reactive plasticizer comprising a vinyl polymer having not    more than one of crosslinking silyl group of the above general    formula (1) on the average per molecule.

Lastly, the fifth aspect of the present invention is directed to acurable composition comprising

-   (A5) a vinyl polymer having at least one crosslinking silyl group of    the above general formula (1) on the average (provided, however,    that R¹ and R² may be the same or different and each represents an    alkyl group containing 1 to 20 carbon atoms, an aryl group    containing 6 to 20 carbon atoms or an aralkyl group containing 7 to    20 carbon atoms), the main chain of which vinyl polymer has been    obtained by a living polymerization reaction and-   (F) a compound having one silanol group per its molecule and/or a    compound capable of reacting with moisture to give a compound having    one silanol group per the molecule.

The present invention is now described in detail.

DETAILED DISCLOSURE OF THE INVENTION

<<First Aspect of the Invention>>

The curable composition according to the first aspect of the inventionis now described in detail.

The curable composition according to the first aspect of the inventioncomprises (A1) a vinyl polymer having a crosslinking silyl group and (B)a photocurable substance.

[(A1) Vinyl Polymer]

The vinyl polymer having at least one crosslinking silyl group of theabove general formula (1) on the average, for use as (A1) component,crosslinks by siloxane bonding.

<Main Chain>

The vinyl monomer constituting the main chain of the vinyl polymer (A1)is not particularly restricted but may be any of various monomers. Asexamples, there may be mentioned (meth)acrylic monomers such as(meth)acrylic acid, methyl (meth)acrylate, ethyl(meth)acrylate,n-propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate,isobutyl (meth)acrylate, tert-butyl(meth)acrylate, n-pentyl(meth)acrylate, n-hexyl(meth)acrylate, cyclohexyl (meth)acrylate,n-heptyl(meth)acrylate, n-octyl (meth)acrylate,2-ethylhexyl(meth)acrylate, nonyl (meth)acrylate, decyl(meth)acrylate,dodecyl(meth)acrylate, phenyl(meth)acrylate, toluyl(meth)acrylate,benzyl (meth)acrylate, 2-methoxyethyl(meth)acrylate,3-methoxybutyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, stearyl(meth)acrylate,glycidyl(meth)acrylate, 2-aminoethyl(meth)acrylate,γ-(methacryloyloxypropyl)trimethoxysilane, (meth)acrylic acid-ethyleneoxide adducts, trifluoromethylmethyl (meth)acrylate,2-trifluoromethylethyl(meth)acrylate,2-perfluoroethylethyl(meth)acrylate,2-perfluoroethyl-2-perfluorobutylethyl(meth)acrylate, 2-perfluoroethyl(meth)acrylate, perfluoromethyl(meth)acrylate,diperfluoromethylmethyl(meth)acrylate,2-perfluoromethyl-2-perfluoroethylmethyl(meth)acrylate,2-perfluorohexylethyl (meth)acrylate,2-perfluorodecylethyl(meth)acrylate and2-perfluorohexadecylethyl(meth)acrylate; styrenic monomers such asstyrene, vinyltoluene, α-methylstyrene, chlorostyrene, andstyrenesulfonic acid and salts thereof; fluorine-containing vinylmonomers such as perfluoroethylene, perfluoropropylene and vinylidenefluoride; silicon-containing vinyl monomers such asvinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleicacid and monoalkyl esters and dialkyl esters of maleic acid; fumaricacid and monoalkyl esters and dialkyl esters of fumaric acid; maleimidemonomers such as maleimide, methylmaleimide, ethylmaleimide,propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide,dodecylmaleimide, stearylmaleimide, phenylmaleimide andcyclohexylmaleimide; nitrile-containing vinyl monomers such asacrylonitrile and methacrylonitrile; amido-containing vinyl monomerssuch as acrylamide and methacrylamide; vinyl esters such as vinylacetate, vinyl propionate, vinyl pivalate, vinyl benzoate and vinylcinnamate; alkenes such as ethylene and propylene; conjugated dienessuch as butadiene and isoprene; vinyl chloride, vinylidene chloride,allyl chloride, allyl alcohol and so forth. These may be used singly ora plurality of them may be copolymerized. Preferred among them from theviewpoint of physical properties of products, among others, are styrenicmonomers and (meth)acrylic monomers, more preferably acrylic estermonomers and (meth)acrylic ester monomers, still more preferably acrylicester monomers, and butyl acrylate is particularly preferred. In thepractice of the invention, these preferred monomers may be copolymerizedwith other monomers, even in the manner of block polymerization, and, onthat occasion, the proportion of these preferred monomers is preferably40% by weight. In the nomenclature used above, (meth)acrylic acid, forinstance, means acrylic acid and/or methacrylic acid.

The molecular weight distribution of the vinyl polymer (A1) is notparticularly restricted but the ratio of weight average molecular weightto number average molecular weight as determined by gel permeationchromatography is generally less than 1.8, preferably not more than 1.7,more preferably not more than 1.6, still more preferably not more than1.5, especially preferably not more than 1.4, most preferably not morethan 1.3. In GPC measurements in the practice of the invention, themeasurements are generally carried out using polystyrene gel columnswith chloroform as the mobile phase. The number average molecular weightand so on can be determined on a polystyrene equivalent basis.

The number average molecular weight of the vinyl polymer (A1) is notparticularly restricted but preferably is within the range of 500 to1,000,000, more preferably 1,000 to 100,000.

<Methods for Synthesis of the Main Chain>

The method of synthesizing the vinyl polymer (A1) is not restricted butis preferably a controlled radical polymerization technique, morepreferably a living radical polymerization technique, particularly anatom transfer radical polymerization technique. These polymerizationtechniques are described below.

Controlled Radical Polymerization

The radical polymerization method can be divided into the “generalradical polymerization method” in which a monomer having a givenfunctional group is simply copolymerized with a vinyl monomer using anazo or peroxide compound as the polymerization initiator and the“controlled radical polymerization method” which is capable ofintroducing a given functional group into a defined position such as themolecular chain terminus.

The “general radical polymerization method” is an expedient method.However, by this method, a monomer having a given functional group isintroduced into the product polymer only in probabilities, and in orderto synthesize a polymer of high functionality, this monomer must be usedin a fairly large amount. When conversely the amount of the monomer issmall, the ratio of polymer molecules not provided with the givenfunctional group is increased. Another disadvantage is that since thereaction is a free radical polymerization reaction, the molecular weightdistribution is so broadened that only a polymer having a high viscositycan be obtained.

The “controlled radical polymerization method” can be divided into the“chain transfer agent technique” in which a vinyl polymer having afunctional group at the molecular chain terminus is produced by carryingout the polymerization reaction using a chain transfer agent having agiven functional group, and the “living radical polymerizationtechnique” in which the polymerization proceeds with the growing chainterminus constantly growing without being interrupted by a terminationreaction to give a polymer approximating the designed molecular weight.

The “chain transfer agent technique” is capable of giving a polymer ofhigh functionality but a chain transfer agent having a given functionalgroup must be used in a fairly large amount relative to the initiator,with the consequent disadvantage in economics inclusive of the cost oftreatment involved. A further disadvantage of the technique is thatbecause it is also a free radical polymerization method as is said“general radical polymerization method”, there can be obtained only apolymer having a broad molecular weight distribution and a highviscosity.

Unlike the above polymerization technology, the “living radicalpolymerization technique” is advantageous in that despite its also beinga method for radical polymerization reaction which is generallyconsidered to be hardly controllable because of the high velocitypolymerization and high tendency of termination by radical-radicalcoupling or the like, a termination reaction does not easily take place,thus giving a polymer with a narrow molecular weight distribution(Mw/Mn=about 1.1 to 1.5), and further in that the molecular weight canbe freely controlled by adjusting the monomer-initiator charge ratio.

Since “living radical polymerization” is thus capable of giving apolymer having a narrow molecular weight distribution and a lowviscosity and enables introduction of a monomer having a givenfunctional group in an almost designated position, it is a furtherpreferred method for producing a vinyl polymer having said givenfunctional group.

In a narrow sense of the term, “living polymerization” means apolymerization in which the molecule grows with its growth termini beingconstantly activated. Generally, however, the term is used to broadlycover as well a pseudo-living polymerization reaction in which thepolymer grows while molecules with an activated terminus and moleculeswith an inactivated terminus are in equilibrium, and the term as used inthis specification also has the latter broad meaning.

Recently, “living radical polymerization” has been studied in earnest bymany research groups. By way of illustration, this technology includesthe method employing a cobalt porphyrin complex as described in J. Am.Chem. Soc., 116, 7943 (1994); the method using a radical rapping agentsuch as a nitroxide compound as described in Macromolecules, 27, 7228(1994), and the atom transfer radical polymerization (ATRP) method usingan organohalogen compound as the initiator and a transition metalcomplex as the catalyst.

Among such variations of the “living radical polymerization method”, the“atom transfer radical polymerization” method in which a vinyl monomeris polymerized using an organohalogen compound or a sulfonyl halidecompound as the initiator and a transition metal complex as the catalystis still more preferred for the production of said vinyl polymer havinga given functional group because, in addition to the above-mentionedadvantages of “living radical polymerization”, it is capable of giving apolymer having a halogen atom or the like at its terminus, which iscomparatively favorable for a functional group exchange reaction, andoffers a broad freedom in the initiator and catalyst design. Regardingthis atom transfer radical polymerization method, reference-can be madeto Matyjaszewski et al.: J. Am. Chem. Soc., 117, 5614 (1995)Macromolecules, 28, 7901 (1995), Science, 272, 866 (1996), WO 96/30421,WO 97/18247, WO 98/01480, WO 98/40415, Sawamoto et al.: Macromolecules,28, 1721 (1995), Japanese Kokai Publication Hei-9-208616 and JapaneseKokai Publication Hei-8-41117, among others.

The technique to be selected from among those living radicalpolymerization techniques in the practice of the present invention isnot particularly restricted but atom transfer radical polymerization ispreferred.

Living radical polymerization will be described in detail hereinafter.In the first place, however, the polymerization reaction using a chaintransfer agent, which is a variant of controlled radical polymerization,for the production of vinyl polymer (A1) to be described hereinafter, isnow explained. While the radical polymerization technique utilizing achain transfer agent (telomer) is not particularly restricted but forthe production of a vinyl polymer having a terminal structure suited tothe present invention, the following two alternative techniques, amongothers, can be mentioned.

These include the process for producing a halogen-terminated polymerusing a halogenated hydrocarbon as a chain transfer agent as describedin Japanese Kokai Publication Hei-4-132706 and the process for producinga hydroxyl-terminated polymer using an OH-containing mercaptan, anOH-containing polysulfide or the like as the chain transfer agent asdescribed in Japanese Kokai Publication Sho-61-271306, Japanese Patent2594402, and Japanese Kokai Publication Sho-54-47782.

The living radical polymerization technique is now explained.

First, the technique which uses a radical capping agent such as anitroxide compound is described. In this polymerization, a nitroxy freeradical (═N—O.), which is generally stable, is used as the radicalcapping agent. While such a compound is not restricted, nitroxy freeradicals from cyclic hydroxylamines, such as the2,2,6,6-substituted-1-piperidinyloxy radical and2,2,5,5-substituted-1-pyrrolidinyloxy radical, are preferred.Appropriate as the substituents are alkyl groups containing not morethan 4 carbon atoms, such as methyl and ethyl groups. Specific nitroxyfree radical compounds include, but are not limited to,2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO),2,2,6,6-tetraethyl-1-piperidinyloxy radical,2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxy radical,2,2,5,5-tetramethyl-1-pyrrolidinyloxy radical,1,1,3,3-tetramethyl-2-isoindolinyloxy radical andN,N-di-tert-butylaminoxy radical, among others. Such a stable freeradical as the galvinoxyl free radical may be used in lieu of thenitroxy free radical.

The above radical capping agent is used in combination with a radicalgenerator. It is presumable that the reaction product from a radicalcapping agent and a radical generator serves as a polymerizationinitiator and the polymerization of an addition-polymerizable monomer(s)proceeds. The mixing ratio of the two agents is not particularlyrestricted but, appropriately, the radical initiator is used in anamount of 0.1 to 10 moles per mole of the radical capping agent.

Although various compounds can be used as the radical generator, aperoxide capable of generating a radical under polymerizationtemperature conditions is preferred. Such peroxide includes but is notlimited to diacyl peroxides such as benzoyl peroxide and lauroylperoxide, dialkyl peroxides such as dicumyl peroxide and di-tert-butylperoxide, peroxydicarbonates such as diisopropyl peroxydicarbonate andbis(4-tert-butylcyclohexyl)peroxydicarbonate, alkyl peresters such astert-butyl peroxyoctoate and tert-butyl peroxybenzoate, and the like. Inparticular, benzoyl peroxide is preferred. Further, another radicalgenerator, for example a radical-generating azo compound such asazobisisobutyronitrile, may be used in lieu of the peroxide.

As reported in Macromolecules, 1995, 28, 2993, such alkoxyaminecompounds as shown below may be used as the initiator instead of thecombined use of a radical capping agent and a radical generator.

When an alkoxyamine compound is used as the initiator and the compoundhas a hydroxyl or like functional group, as indicated by either formulashown above, a functional group-terminated polymer is obtained. Whenthis is applied to the method of the invention, a functionalgroup-terminated vinyl polymer is obtained.

The monomer(s) to be used in the polymerization using a radical cappingagent such as a nitroxide compound as mentioned above and thepolymerization conditions such as solvent and polymerization temperatureare not restricted but may be the same as those used in atom transferradical polymerization to be described below.

Atom Transfer Radical Polymerization

Then, the technique of atom transfer radical polymerization, which ismore preferred as the technique of living radical polymerization, isdescribed.

In this atom transfer radical polymerization, an organohalogen compound,in particular an organohalogen compound having a highly reactivecarbon-halogen bond (e.g. a carbonyl compound having a halogen atom atthe a position, or a compound having a halogen at the benzyl position),or a sulfonyl halide compound or the like is used as the initiator.

Specific examples are:C₆H₅—CH₂X, C₆H₅—C(H)(X)CH₃, C₆H₅—C(X)(CH₃)₂(in the above formulas, C₆H₅ stands for a phenyl group; X is a chlorine,bromine or iodine atom),R³—C(H)(X)—CO₂R⁴, R³—C(CH₃)(X)—CO₂R⁴, R³—C(H)(X)—C(O)R⁴,R³—C(CH₃)(X)—C(O)R⁴(in the above formula, R³ and R⁴ each represents a hydrogen atom or analkyl, aryl or aralkyl group containing up to 20 carbon atoms; X is achlorine, bromine or iodine atom),R³—C₆H₄—SO₂X(in the above formula, R³ is a hydrogen atom or an alkyl, aryl oraralkyl group containing up to 20 carbon atoms and X is a chlorine,bromine or iodine atom), and so on.

An organohalogen or sulfonyl halide compound having a functional groupother than a functional group serving as an initiator of thepolymerization may also be used as the initiator in atom transferradical polymerization. In such cases, there is formed a vinyl polymerhaving said functional group at one terminus of the main chain with theother terminus having the growing terminal structure for atom transferradical polymerization. As such functional group, there may be mentionedan alkenyl group, a crosslinking silyl group, a hydroxyl group, an epoxygroup, an amino group, an amido group and the like.

The alkenyl-containing organohalogen compound includes but is notlimited to compounds having a structure represented by the generalformula (2):R⁶R⁷C(X)—R⁸—R⁹—C(R⁵)═CH₂  (2)wherein R⁵ is a hydrogen atom or a methyl group; R⁶ and R⁷ eachrepresents a hydrogen atom or a univalent alkyl, aryl or aralkyl groupcontaining up to 20 carbon atoms or these are linked to each other atthe respective free termini; R⁸ is —C(O)O— (ester group), —C(O)— (ketogroup) or an o-, m- or p-phenylene group; R⁹ is a direct bond or abivalent organic group containing 1 to 20 carbon atoms, which mayoptionally contain one or more ether linkages; X is a chlorine, bromineor iodine atom.

As specific examples of the substituents R⁶ and R⁷, there may bementioned hydrogen, methyl, ethyl, n-propyl, isopropyl, butyl, pentyl,hexyl and the like. R⁶ and R⁷ may be linked to each other at therespective free termini to form a cyclic structure.

Specific examples of the alkenyl-containing organohalogen compoundrepresented by the general formula (2) are as follows:XCH₂C(O)O(CH₂)_(n)CH═CH₂, H₃CC(H)(X)C(O)O(CH₂)_(n)CH═CH₂,(H₃C)₂C(X)C(O)O(CH₂)_(n)CH═CH₂, CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)CH═CH₂,

(in the above formulas, X is a chlorine, bromine or iodine atom and n isan integer of 0 to 20);XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂, H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)CH═CH₂,

(in the above formulas, X is a chlorine, bromine or iodine atom; n is aninteger of 1 to 20; m is an integer of 0 to 20);o, m, p-XCH₂—C₆H₄—(CH₂)—CH═CH₂, o, m,p-CH₃C(H)(X)—C₆H₄—(CH₂)_(n)—CH═CH₂, o, m, p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)_(n)—CH═CH₂,(in the above formulas, X is a chlorine, bromine or iodine atom; n is aninteger of 0 to 20);o, m, p-XCH₂—C₆H—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂, o, m,p-CH₃C(H)(X)—C₆H₄—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂,(in the above formulas, X is a chlorine, bromine or iodine atom; n is aninteger of 1 to 20; m is an integer of 0 to 20);o, m, p-XCH₂—C₆H₄—O—(CH₂)_(n)—CH═CH₂, o, m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)_(n)—CH═CH₂, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)_(n)—CH═CH₂,(in the above formulas, X is a chlorine, bromine or iodine atom; n is aninteger of 0 to 20);o, m, p-XCH₂—C₆H₄—O—(CH₂)—O—(CH₂)_(m)—CH═CH₂, o, m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)_(n)—O—(CH₂)_(m)—CH═CH₂, o, m, p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)—O—(CH₂)_(m)—CH═CH₂,(in the above formulas, X is a chlorine, bromine or iodine atom; n is aninteger of 1 to 20; m is an integer of 0 to 20).

As the alkenyl-containing organohalogen compound, there may further bementioned compounds represented by the general formula (3):H₂C═C(R⁵)—R⁹—C(R⁶)(X)—R¹⁰R⁷  (3)wherein R⁵, R⁶, R⁷, R⁹ and X are as defined above and R¹⁰ represents adirect bond, —C(O)O— (ester group), —C(O)— (keto group) or an o-, m- orp-phenylene group.

R⁸ is a direct bond or a bivalent organic group containing 1 to 20carbon atoms (which may optionally contain one or more ether linkages)and, when it is a direct bond, the vinyl group is attached to the carbonatom to which the halogen atom is attached, hence the compound is anallyl halide. In this case, the carbon-halogen bond is activated by theneighboring vinyl group and therefore it is not always necessary for R¹⁰to be a C(O)O or phenylene group; thus, R¹⁰ may be a direct bond. WhenR⁹ is not a direct bond, it is desirable that R¹⁰ is a C(O)O, C(O) orphenylene group so as to activate the carbon-halogen bond.

Specific examples of the compound of formula (3) are as follows:CH₂═CHCH₂X, CH₂═C(CH₃)CH₂X, CH₂═CHC(H)(X) CH₃, CH₂═C(CH₃)C(H)(X)CH₃,CH₂═CHC(X)(CH₃)₂, CH₂═CHC(H)(X)C₂H₅, CH₂═CHC(H)(X)CH(CH₃)₂,CH₂═CHC(H)(X)C₆H₅, CH₂═CHC(H)(X)CH₂C₆H₅, CH₂═CHCH₂C(H)(X)—CO₂R,CH₂═CH(CH₂)₂C(H)(X)—CO₂R, CH₂═CH(CH₂)₃C(H)(X)—CO₂R,CH₂═CH(CH₂)₈C(H)(X)—CO₂R, CH₂═CHCH₂C(H)(X)—C₆H₅,CH₂═CH(CH₂)₂C(H)(X)—C₆H₅, and CH₂═CH(CH₂)₃C(H)(X)—C₆H₅(in the above formulas, X represents a chlorine, bromine or iodine atom;R is an alkyl, aryl or aralkyl group containing up to 20 carbon atoms),and the like.

Specific examples of the alkenyl-containing sulfonyl halide compound areas follows:o-, m-, p-CH₂═CH—(CH₂)_(n)—C₆H₄—SO₂X ando-, m-, p-CH₂═CH—(CH₂)_(n)—O—C₆H₄—SO₂X(in the above formulas, X represents a chlorine, bromine or iodine atom;n is an integer of 0 to 20).

The above crosslinking silyl-containing organohalogen compound includesbut is not limited to compounds having a structure represented by thegeneral formula (4):R⁶R⁷C(X)—R⁸—R⁹—C(H)(R⁵)CH₂—[Si(R¹¹)_(2-b)(Y)_(b)O]_(m)—Si(R¹²)_(3-a)(Y)_(a)  (4)wherein R⁵, R⁶, R⁷, R⁸, R⁹ and X are as defined above; R¹¹ and R¹² eachrepresents an alkyl, aryl or aralkyl group containing up to 20 carbonatoms or a triorganosiloxy group of the formula (R′)₃SiO— (where R′ is aunivalent hydrocarbon group containing 1˜20 carbon atoms and the threeR′ groups may be the same or different) and, when two or more R¹¹ and/orR¹² groups are present, they may be the same or different; Y representsa hydroxyl group or a hydrolyzable group and, when two or more Y groupsare present, they may be the same or different; a represents an integerof 0, 1, 2 or 3, b represents an integer of 0, 1 or 2 and m is aninteger of 0 to 19, with the condition that the relation a+mb≧1 shouldbe satisfied.

Specific examples of the compound of the general formula (4) are:XCH₂C(O)O(CH₂)_(n)Si(OCH₃)₃, CH₃C(H)(X)C(O)O(CH₂)_(n)Si(OCH₃)₃,(CH₃)₂C(X)C(O)O(CH₂)_(n)Si(OCH₃)₃, XCH₂C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,CH₃C(H)(X)C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,(CH₃)₂C(X)C(O)O(CH₂)_(n)Si(CH₃)(OCH₃)₂,(in the above formulas, X represents a chlorine, bromine or iodine atom;a represents an integer of 0 to 20);XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)Si(OCH₃)₃,XCH₂C(O)O(CH₂)_(n)O(CH₂)_(m)Si(CH₃)(OCH₃)₂,H₃CC(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,(H₃C)₂C(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,CH₃CH₂C(H)(X)C(O)O(CH₂)_(n)O(CH₂)_(m)—Si(CH₃)(OCH₃)₂,(in the above formulas, X represents a chlorine, bromine or iodine atom;n represents an integer of 1 to 20; m represents an integer of 0 to 20);o, m, p-XCH₂—C₆H₄—(CH₂)₂Si(OCH₃)₃, o, m,p-CH₃C(H)(X)—C₆H₄—(CH₂)₂Si(OCH₃)₃, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₂Si(OCH₃)₃, o, m, p-XCH₂—C₆H₄—(CH₂)₃Si(OCH₃)₃,o, m, p-CH₃C(H)(X)—C₆H₄—(CH₂)₃Si(OCH₃)₃, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₃Si(OCH₃)₃, o, m,p-XCH₂—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃, o, m,p-CH₃C(H)(X)—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃, o, m,p-XCH₂—CH₄—O—(CH₂)₃Si(OCH₃)₃, o, m, p-CH₃C(H)(X)—C₆H₄—O—(CH₂)₃Si(OCH₃)₃,o, m, p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)₃Si(OCH₃)₃, o, m,p-XCH₂—C₆H₄—O—(CH₂)₂—O—(CH₂)₃—Si—(OCH₃)₃, o, m,p-CH₃C(H)(X)—C₆H₄—O—(CH₂)₂—O—(CH₂)₃—Si(OCH₃)₃, o, m,p-CH₃CH₂C(H)(X)—C₆H₄—O—(CH₂)₂—O—(CH₂)₃Si(OCH₃)₃,(in the above formulas, X represents a chlorine, bromine or iodine atom)and the like.

As further examples of the crosslinking silyl group-containingorganohalogen compound, there may be mentioned compounds having astructure represented by the general formula (5):(R¹²)_(3-a)(Y)_(a)Si—[OSi(R¹¹)_(2-b)(Y)_(b)]_(m)—CH₂—C(H)(R⁵)—R⁹—C(R⁶)(X)—R¹⁰—R⁷  (5)wherein R⁵, R⁶, R⁷, R⁹, R¹⁰, R¹¹, R¹², a, b, m, X and Y are as definedabove.

Specific examples of such compound are as follows:(CH₃O)₃SiCH₂CH₂C(H)(X)C₆H₅, (CH₃O)₂(CH₃)SiCH₂CH₂C(H)(X)C₆H₅,(CH₃O)₃Si(CH₂)₂C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₂C(H)(X)—CO₂R,(CH₃O)₃Si(CH₂)₃C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₃C(H)(X)—CO₂R,(CH₃O)₃Si(CH₂)₄C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₄C(H)(X)—CO₂R,(CH₃O)₃Si(CH₂)₉C(H)(X)—CO₂R, (CH₃O)₂(CH₃)Si(CH₂)₉C(H)(X)—CO₂R,(CH₃O)₃Si(CH₂)₃C(H)(X)—C₆H₅, (CH₃O)₂(CH₃)Si(CH₂)₃C(H)(X)—C₆H₅,(CH₃O)₃Si(CH₂)₄C(H)(X)—C₆H₅, (CH₃O)₂(CH₃)Si(CH₂)₄C(H)(X)—C₆H₅,(in the above formulas, X represents a chlorine, bromine or iodine atom;R represents an alkyl, aryl or aralkyl group containing up to 20 carbonatoms) and the like.

The hydroxyl-containing organohalogen or sulfonyl halide compound is notparticularly restricted but may be a compound of the formula:HO—(CH₂)—OC(O)C(H)(R)(X)wherein X represents a chlorine, bromine or iodine atom; R represents ahydrogen atom or an alkyl, aryl or aralkyl group containing up to 20carbon atoms; n represents an integer of 1 to 20.

The amino-containing organohalogen or sulfonyl halide compound is notparticularly restricted but may be a compound of the formula:H₂N—(CH₂)_(n)—OC(O)C(H)(R)(X)wherein X represents a chlorine, bromine or iodine atom; R represents ahydrogen atom or an alkyl, aryl or aralkyl group containing up to 20carbon atoms; n represents an integer of 1 to 20.

The epoxy-containing organohalogen or sulfonyl halide compound is notparticularly restricted but may be a compound of the formula:

wherein X is a chlorine, bromine or iodine atom; R represents a hydrogenatom or an alkyl, aryl or aralkyl group containing up to 20 carbonatoms; n represents an integer of 1 to 20.

It is preferable to use an organohalogen or sulfonyl halide compoundhaving 2 or more initiation points as the initiator to produce a polymerhaving 2 or more terminal structures of the invention per molecule.Specific examples are:

(in the above formulas, C₆H₄ stands for a phenylene group; X representsa chlorine, bromine or iodine atom)

(in the above formulas, R represents an alkyl, aryl or aralkyl groupcontaining up to 20 carbon atoms; n represents an integer of 0 to 20; Xrepresents a chlorine, bromine or iodine atom)

(in the above formulas, X represents a chlorine, bromine or iodine atom;n represents an integer of 0 to 20)

(in the above formulas, n represents an integer of 0 to 20; X representsa chlorine, bromine or iodine atom)

(in the above formulas, X represents a chlorine, bromine or iodineatom).

The vinyl monomer for this polymerization reaction is not particularlyrestricted but any of the monomers mentioned hereinabove can be employedwith advantage.

The transition metal complex to be used as the polymerization catalystis not particularly restricted but includes, as preferred examples,transition metal complexes whose center metals belong to Group 7, 8, 9,10 or 11 of the periodic table of the elements and, as more preferredspecies, complexes of zero-valence copper, univalent copper, bivalentruthenium, bivalent iron or bivalent nickel. Copper complexes areparticularly preferred. As specific examples of the univalent coppercompound, there may be mentioned cuprous chloride, cuprous bromide,cuprous iodide, cuprous cyanide, cuprous oxide and cuprous perchlorate.When a copper compound is used, a ligand, for example 2,2′-bipyridyl ora derivative thereof, 1,10-phenanthroline or a derivative thereof, or apolyamine such as tetramethylethylenediamine,pentamethyldiethylenetriamine or hexamethyltris(2-aminoethyl)amine, isadded for improving catalytic activity. The tristriphenylphosphinecomplex of bivalent ruthenium chloride (RuCl₂(PPh₃)₃) is also suited foruse as a catalyst. When a ruthenium compound is used as the catalyst, analuminum alkoxide is added as an activator. Further, thebistriphenylphosphine complex of bivalent iron (FeCl₂(PPh₃)₂) thebistriphenylphosphine complex of bivalent nickel (NiCl₂(PPh₃)₂) and thebistributylphosphine complex of bivalent nickel (NiBr₂(PBu₃)₂) are alsosuited as catalysts.

The polymerization can be carried out in the absence of a solvent or inany of various solvents. As the solvents, there may be mentionedhydrocarbon solvents such as benzene and toluene; ether solvents such asdiethyl ether and tetrahydrofuran; halogenated hydrocarbon solvents suchas methylene chloride and chloroform; ketone solvents such as acetone,methyl ethyl ketone and methyl isobutyl ketone; alcohol solvents such asmethanol, ethanol, propanol, isopropyl alcohol, n-butyl alcohol andtert-butyl alcohol; nitrile solvents such as acetonitrile, propionitrileand benzonitrile; ester solvents such as ethyl acetate and butylacetate; carbonate solvents such as ethylene carbonate and propylenecarbonate; and so on. These may be used singly or two or more of themmay be used in admixture. The polymerization can be carried out withinthe temperature range of 0° C. to 200° C., preferably 50 to 150° C.,although such range is not critical.

<Crosslinking Silyl Group>

Crosslinking Silyl Group

The crosslinking silyl group of the vinyl polymer (A1) includes thoserepresented by the general formula (1):—[Si(R¹)_(2-b)(Y)_(b)O]_(m)—Si(R²)_(3-a)(Y)_(a)  (1)wherein R¹ and R² each represents a C₁₋₂₀ alkyl, C₆₋₂₀ aryl or C₇₋₂₀aralkyl group or a triorganosiloxy group represented by (R′)₃SiO— (whereeach R′ represents a C₁₋₂₀ univalent hydrocarbon group and the three R′groups may be the same or different) and, when there are a plurality ofR¹ or R² groups, they may be the same or different; Y represents ahydroxyl group or a hydrolyzable group and, when two or more Y groupsare present, they may be the same or different; a represents an integerof 0, 1, 2 or 3, b represents an integer of 0, 1 or 2 and M representsan integer of 0 to 19 on condition that the relation a+mb≧1 should besatisfied.

The hydrolyzable group may be any of those known in the art and itincludes hydrogen, alkoxy, acyloxy, ketoximato, amino, amido, aminoxy,mercapto and alkenyloxy. Among these, alkoxy, amido and aminoxy arepreferred. For assuring hydrolyzability under mild conditions and easeof handling, alkoxy groups are particularly preferred.

Each silicon atom may have 1 to 3 such hydrolyzable and/or hydroxylgroups, and (a+Σb) is preferably within the range of 1 to 5. When two ormore hydrolyzable groups and/or hydroxyl groups are contained in thecrosslinking silyl group, they may the same or different. Thecrosslinking silyl group is comprised of one or more silicon atoms and,in the case of silicon atoms connected by siloxane bonding, the numberof silicon atoms is preferably up to 20 at the maximum. Fromavailability points of view, crosslinking silyl groups represented bythe general formula (6) are preferred:—Si(R¹²)_(3-a)(Y)_(a)  (6)wherein R¹², Y and a are as defined above.Number of Crosslinking Silyl Groups

The crosslinking silyl group of the general formula (1) occurs in thenumber of at least one on the average per molecule of the polymer (A1).If the average number of crosslinking silyl groups is less than one permolecule, a sufficiently cured product will not be obtained. In order toprovide a fully cured product, the crosslinking Silyl group of thegeneral formula (1) should be available in the average number of 1.1 to5, preferably 1.2 to 4, more preferably 1.3 to 3, per molecule of thepolymer.

Position of the Crosslinking Silyl Group

When the curable composition of the invention is required to give acured product having rubber-like properties in particular, it ispreferable that said at least one crosslinking silyl group is present atthe molecular chain terminus, for the molecular mass betweencrosslinking points, which has considerable bearings on rubberelasticity, can then be large. More preferably, all crosslinking silylgroups are located at molecular chain termini.

The technology of producing a vinyl polymer having at least onecrosslinking silyl group at the molecular chain terminus, particularlysuch a (meth)acrylic polymer, is described in Japanese KokokuPublication Hei-3-14068, Japanese Kokoku Publication Hei-4-55444 andJapanese Kokai Publication Hei-6-211922. However, since these areinvariably free radical polymerization processes utilizing said “chaintransfer agent technique”, the resulting polymer contains crosslinkingsilyl groups at its termini at a fairly high rate but has the drawbackthat the molecular weight distribution value, represented by Mw/Mn, isas large as 2 or more and, hence, the viscosity of the polymer is high.Therefore, in order to provide a vinyl polymer having a small molecularweight distribution value, hence a low viscosity value, and, yet,crosslinking silyl groups at its termini at a fairly high rate, the“living radical polymerization technique” mentioned hereinbefore ispreferably employed.

<Method of Introducing a Crosslinking Silyl Group>

The technology of introducing a functional group into the vinyl polymerincludes but is not limited to the following methods.

-   [A] The method which comprises adding a hydrosilane compound having    a crosslinking silyl group to a vinyl polymer having at least one    alkenyl group in the presence of a hydrosilylation catalyst.-   [B] The method which comprises reacting a vinyl polymer having at    least one hydroxyl group with a compound having both a crosslinking    silyl group and a functional group capable of reacting with the    hydroxyl group, for example an isocyanato group.-   [C] The method which comprises subjecting to reaction of a compound    having both a polymerizable alkenyl group and a crosslinking silyl    group, together with a predetermined vinyl monomer, in synthesizing    a vinyl polymer by radical polymerization.-   [D] The method which comprises subjecting a vinyl monomer to radical    polymerization using a crosslinking silyl group-containing chain    transfer agent.-   [E] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with a stable,    crosslinking silyl group-containing carbanion.

The method of producing the vinyl polymer having at least one alkenylgroup which is to be used in the above production method [A] includesbut is not limited to the following methods [A-a] to [A-j].

-   [A-a] The method which comprises subjecting a compound having a    polymerizable alkenyl group and a sparingly polymerizable alkenyl    group, e.g. a compound of the general formula (7), together with a    predetermined vinyl monomer, to reaction in synthesizing a vinyl    polymer by radical polymerization.    H₂C═C(R³)—R⁴—R⁵—C(R⁶)═CH₂  (7)    wherein R³ represents a hydrogen atom or methyl group; R⁴ represents    —C(O)O— or an o-, m- or p-phenylene group; R⁵ represents a direct    bond or a C₁₋₂₀ bivalent organic group which may optionally contain    one or more ether linkages; R⁶ represents a hydrogen atom, a C₁₋₁₀    alkyl group, C₆₋₁₀ aryl group or C₇₋₁₀ aralkyl group.

The timing of reacting said compound having both a polymerizable alkenylgroup and a sparingly polymerizable alkenyl group is not particularlyrestricted but, when rubber-like properties are expected of the obtainedcrosslinked product, this compound is preferably reacted, as a secondmonomer, at a terminal stage of polymerization or after completion ofthe reaction of the vinyl monomer.

-   [A-b] The method in which, in synthesizing a vinyl polymer by living    radical polymerization, a compound having at least 2 sparingly    polymerizable alkenyl groups, such as 1,5-hexadiene, 1,7-octadiene    or 1,9-decadiene, is reacted at a terminal stage of polymerization    or after completion of the reaction of the vinyl monomer.

The following methods [A-c]˜[A-f] can be used for producing a vinylpolymer having at least one alkenyl group from a vinyl polymer having atleast one highly reactive carbon-halogen bond. The above polymer havingat least one highly reactive carbon-halogen bond can be prepared by theprocesses [E-a] and [E-b] to be described hereinafter.

-   [A-c] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with an organometal    compound having an alkenyl group, typically represented by organotin    compounds such as allyltributyltin, allyltrioctyltin, etc., to    substitute an alkenyl-containing substituent for the halogen.-   [A-d] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with a stabilized    carbanion having an alkenyl group, which may for example be    represented by the general formula (8), to substitute an alkenyl    group for the halogen.    M⁺C⁻(R⁷)(R⁸)—R⁹—C(R⁶)═CH₂  (8)    (wherein R⁶ is as defined above; R⁷ and R⁸ each represents an    electron-withdrawing group which stabilizes the carbanion C⁻ or one    of these represents said electron-withdrawing group with the other    being hydrogen, an alkyl group containing 1 to 10 carbon atoms or a    phenyl group; R⁹ represents a direct bond or a C₁₋₁₀ bivalent    organic group which may contain one or more ether linkages; M⁺    represents an alkali metal ion or a quaternary ammonium ion). As the    electron-withdrawing group for R⁷ and R⁸, a group represented by the    formula —CO₂R, —C(O)R or —CN is particularly preferred. In the above    formula, R represents hydrogen or an alkyl containing 1 to 10 carbon    atoms, an aryl containing 6 to 10 carbon atoms or an aralkyl group    containing 7 to 10 carbon atoms.-   [A-e] The method which comprises permitting an elemental metal, e.g.    zinc, or an organometal compound to act upon a vinyl polymer having    at least one highly reactive carbon-halogen bond to prepare an    enolate anion and, then, reacting it with an electrophilic compound    having an alkenyl group, such as an alkenyl-containing compound    having a leaving group, e.g. halogen or acetyl, a carbonyl compound    having an alkenyl group, an isocyanate compound having an alkenyl    group or an acid halide having an alkenyl group.-   [A-f] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with an    alkenyl-containing oxyanion, such as the one represented by the    general formula (9), or an alkenyl-containing carboxylate anion,    such as the one represented by the general formula (10), to    substitute an alkenyl-containing substituent for the halogen.    H₂C═C(R⁶)—R¹⁰—O⁻M⁺  (9)    (wherein R⁶ and M⁺ are as defined above; R¹⁰ represents a C₁₋₂₀    bivalent organic group which may contain one or more ether linkages)    H₂C═C(R⁶)—R¹¹—C(O)O⁻M⁺  (10)    (wherein R⁶ and M⁺ are as defined above; R¹¹ represents a direct    bond or a C₁₋₂₀ bivalent organic group which may contain one or more    ether linkages)

The vinyl polymer having at least one alkenyl group can also be producedfrom a vinyl polymer having at least one hydroxyl group. The specificmethod is not particularly restricted but includes the followingmethods. [A-g] to [A-j] among others. The starting vinyl polymer havingat least one hydroxyl group can be prepared by the methods [B-a] to[B-i] to be described hereinafter

-   [A-g] The method which comprises permitting a base, such as sodium    hydroxide, sodium methoxide, etc., to act on a vinyl polymer having    at least one hydroxyl group and then reacting the same with an    alkenyl-containing halide such as allyl chloride;-   [A-h] The method which comprises reacting an alkenyl-containing    isocyanate compound, such as allyl isocyanate or the like, with a    vinyl polymer having at least one hydroxyl group;-   [A-i] The method which comprises reacting an alkenyl-containing acid    halide, such as (meth)acryloyl chloride, with a vinyl polymer having    at least one hydroxyl group in the presence of a base such as    pyridine; and-   [A-j] The method which comprises reacting an alkenyl-containing    carboxylic acid, such as acrylic acid, with a vinyl polymer having    at least one hydroxyl group in the presence of an acid catalyst.

Referring to the synthesis of said vinyl polymer having at least onealkenyl group, when a halogen is not directly involved in theintroduction of the alkenyl group as in the methods [A-a] and [A-b], itis preferable to use the living radical polymerization technique.Between the above methods, the method [A-b] is preferred in view of therelative ease of control. Among variations of living radicalpolymerization, atom transfer radical polymerization is preferred.

When an alkenyl group is to be introduced by converting the halogengroup of a vinyl polymer having at least one highly reactivecarbon-halogen bond as in the methods [A-c] to [A-f], it is preferableto use a vinyl polymer having at least one highly reactive terminalcarbon-halogen bond as obtained by a radical polymerization (atomtransfer radical polymerization) using an organohalogen compound or asulfonyl halide as the initiator and a transition metal complex as thecatalyst. More preferred is the method [A-f] in consideration of theease of control.

The hydrosilane compound having a crosslinking silyl group for use inthe above synthetic method [A] is not particularly restricted butincludes compounds represented by the following general formula (11),among others.H—[Si(R¹)_(2-b)(Y)_(b)O]_(m)—Si(R²)_(3-a)(Y)_(a)  (11)wherein R¹, R², a, b, m and Y are as defined hereinbefore.

Among these compounds, compounds of the following general formula (12)are preferred from availability points of view.H—Si(R²)_(3-a)(Y)_(a)  (12)wherein R², Y and a are as defined above.

In adding said hydrosilane compound having a crosslinking silyl group tothe alkenyl group of said polymer in said synthetic method [A], atransition metal complex catalyst is generally used as thehydrosilylation catalyst.

The transition metal catalyst mentioned above is not particularlyrestricted but includes, among others, platinum metal and a dispersionof solid platinum in a matrix such as alumina, silica, carbon black orthe like; chloroplatinic acid; a complex of chloroplatinic acid with analcohol, aldehyde or ketone; platinum-olefin complexes andplatinum(0)-divinyltetramethyldisiloxane complex; and compounds otherthan platinum compounds, such as RhCl(PPh₃)₃, RhCl₃, RuCl₃, IrCl₃,FeCl₃, AlCl₃, PdCl₂.H₂O, NiCl₂ and TiCl₄, among others. These catalystscan be used independently or two or more of them may be used in acombination of two or more thereof.

The method of synthesizing said vinyl polymer having at least onehydroxyl group for use in the above synthetic method [B] and further inthe above methods [A-g] to [A-j] is not particularly restricted butincludes the following methods [B-a] to [B-i].

-   [B-a] The method in which, in synthesizing a vinyl polymer by    radical polymerization, a compound having both a polymerizable    alkenyl group and a hydroxyl group, such as the compound represented    by the following general formula (13), is reacted along with the    predetermined vinyl monomer.    H₂C═C(R³)—R⁴—R⁵—OH  (13)    (wherein R³, R⁴ and R⁵ are as defined above)

The timing of reacting said compound having both a polymerizable alkenylgroup and a hydroxyl group is not particularly restricted but, whenrubber-like properties are expected of the crosslinked productobtainable by living radical polymerization, this compound is preferablyreacted, as a second monomer, at a terminal stage of polymerization orafter completion of the reaction of said predetermined vinyl monomer.

-   [B-b] The method in which, in synthesizing a vinyl polymer by living    radical polymerization, an alkenyl alcohol such as 10-undecenol,    5-hexenol or allyl alcohol is reacted at a terminal stage of    polymerization or after completion of the reaction of the    predetermined monomer.-   [B-c] The method for radical polymerization of a vinyl monomer, as    described in Japanese Kokai Publication Hei-5-262808, which    comprises using a hydroxyl-containing chain transfer agent, such as    a hydroxyl-containing polysulfide, in a large quantity.-   [B-d] The method for radical polymerization of a vinyl monomer which    comprises using hydrogen peroxide or a hydroxyl-containing initiator    as described in Japanese Kokai Publication Hei-6-239912 and Japanese    Kokai Publication Hei-8-283310, for instance.-   [B-e] The method for radical polymerization of a vinyl monomer which    comprises using an alcohol in excess as described in Japanese Kokai    Publication Hei-6-116312.-   [B-f] The method which comprises hydrolyzing the halogen of a vinyl    polymer containing at least one highly reactive carbon-halogen bond    or reacting it with a hydroxyl-containing compound to introduce a    hydroxyl group into the polymer terminus as described in Japanese    Kokai Publication Hei-4-132706.-   [B-g] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with a    hydroxyl-containing stabilized carbanion, such as the one    represented by the following general formula (14), to substitute a    hydroxyl-containing substituent for the halogen.    M⁺C⁻(R⁷)(R⁸)—R⁹—OH  (14)    (wherein R⁷, R⁸ and R⁹ are as defined above). As the    electron-withdrawing groups for R⁷ and R⁸, —CO₂R, —C(O)R and —CN are    preferred. In the above formulas, R is as defined above.-   [B-h] The method which comprises permitting an elemental metal, e.g.    zinc, or an organometal compound to act on a vinyl polymer having at    least one highly reactive carbon-halogen bond to prepare an enolate    anion and then reacting it with an aldehyde or a ketone.-   [B-i] The method which comprises reacting a vinyl polymer having at    least one highly reactive carbon-halogen bond with a    hydroxyl-containing oxyanion, such as the one represented by the    general formula (15), or a hydroxyl-containing carboxylate anion,    such as the one represented by the general formula (16) to    substitute a hydroxyl-containing substituent for the halogen.    HO—R¹⁰—O⁻M⁺  (15)    (wherein R¹⁰ and M⁺ are both as defined above)    HO—R¹¹—C(O)O⁻M⁺  (16)    (wherein R¹¹ and M⁺ are both as defined above)

Referring to the synthesis of said vinyl polymer having at least onehydroxyl group, when a halogen is not directly involved in theintroduction of a hydroxyl group as in the above methods [B-a] to [B-e],the living radical polymerization technique is preferred. Inconsideration of the ease of control, the method [B-b] is preferred.Among variations of living radical polymerization, atom transfer radicalpolymerization is preferred.

When the halogen of a vinyl polymer having at least one highly reactivecarbon-halogen bond is to be converted for the introduction of a hydroxygroup as in the above methods [B-f] to [B-i], it is preferable to use avinyl polymer having at least one highly reactive carbon-halogen bond atthe terminus which has been obtained by the radical polymerization (atomtransfer radical polymerization) using an organohalogen or sulfonylhalide compound as the initiator and a transition metal complex as thecatalyst. In consideration of the ease of control, the method [B-i] isstill more preferred.

The compound having both a crosslinking silyl group and an isocyanato orother functional group capable of reacting with a hydroxyl group whichis to be used in the above production method [B] is not particularlyrestricted but includes, among others,γ-isocyanatopropyltrimethoxysilane,γ-isocyanatopropylmethyldimethoxysilane andγ-isocyanatopropyltriethoxysilane. These may be used singly or two ormore of them may be used combinedly.

In carrying out the reaction according to the above production method[B], a urethane formation reaction catalyst known in the art may beused.

The compound having both a polymerizable alkenyl group and acrosslinking silyl group to be used in the above production method [C]is not particularly restricted but includes, among others, compoundsrepresented by the general formula (17) shown below, for exampletrimethoxysilylpropyl(meth)acrylate andmethyldimethoxysilylpropyl(meth)acrylate:H₂C═C(R³)—R⁴—R¹²—[Si(R¹)_(2-b)(Y)_(b)O]_(m)—Si(R²)_(3-a)(Y)_(a)  (17)wherein R¹, R², R³, R⁴, Y, a, b and m are as defined above; R¹²represents a direct bond or a C₁₋₂₀ bivalent organic group optionallycontaining one or more ether linkages. These may be used singly or twoor more of them may be used in combination.

In the above synthetic method [C], the timing of reacting said compoundhaving both a polymerizable alkenyl group and a crosslinking silyl groupis not particularly restricted but, when rubber-like properties areexpected of the crosslinked product obtained by living radicalpolymerization, this compound is preferably reacted, as a secondmonomer, at a terminal stage of polymerization or after completion ofthe reaction of the predetermined vinyl monomer.

The chain transfer agent having a crosslinking silyl group for use inthe above synthetic method [D] is not particularly restricted butincludes crosslinking silyl group-containing mercaptan compounds andhydrosilane compounds having a crosslinking silyl group as disclosed inJapanese Kokoku Publication Hei-3-14068 and Japanese Kokoku PublicationHei-4-55444, among others.

In the radical polymerization of a vinyl monomer, by reacting a compoundhaving both a polymerizable alkenyl group and a crosslinking silyl groupas represented by the above general formula (17) along with acrosslinking silyl group-containing chain transfer agent and thepredetermined vinyl monomer, the amount of the crosslinking silyl groupintroduced can be controlled as desired. Furthermore, in order toenhance the rate of introduction of the crosslinking silyl group, aradical initiator having the crosslinking silyl group can also be usedin combination.

The method of synthesizing the vinyl polymer having at least one highlyreactive carbon-halogen bond for use in the above synthetic method [E]and further in the above methods [A-c] to [A-f] and [B-f] to [B-i] isnot particularly restricted but includes the following processes [E-a]and [E-b].

-   [E-a] A radical polymerization process which, as described in, inter    alia, Japanese Kokai Publication Hei-4-132706, comprises using a    halogen compound, such as carbon tetrachloride, ethylene chloride,    carbon tetrabromide, methylene bromide or the like, as the chain    transfer agent (chain transfer agent technique).-   [E-b] An atom transfer radical polymerization process which    comprises using an organohalogen compound or a sulfonyl halide    compound as the initiator and a transition metal complex as the    catalyst.

The crosslinking silyl group-containing stabilized carbanion for use inthe above synthetic method [E] is not particularly restricted butincludes compounds represented by the following general formula (18),among others.M⁺C⁻(R⁷)(R⁸)—R¹³—C(H)(R¹⁴)—CH₂—[Si(R¹)_(2-b)(Y)_(b)O]_(m)—Si(R²)_(3-a)  (18)wherein R¹, R², R⁷, R⁸, Y, a, b and m are respectively as definedhereinbefore; R¹³ represents a direct bond or a bivalent organic groupof 1 to 20 carbon atoms which may optionally contain one or more etherlinkages; R¹⁴ represents a hydrogen atom, an alkyl group containing 1 to10 carbon atoms, an aryl group containing 6 to 10 carbon atoms or anaralkyl group containing 7 to 10 carbon atoms; R⁷ and R⁸ each representsan electron-withdrawing group which is preferably —CO₂R, —C(O)R or —CN,where R has the same meaning as defined hereinbefore.

When the curable composition according to the first aspect of theinvention is required to give a cured product having rubber-likeproperties in particular, it is preferable that at least onecrosslinking silyl group is present at the molecular chain terminus, forthe molecular mass between crosslinking points, which has considerablebearings on rubber elasticity, can then be large. More preferably, allcrosslinking silyl groups are located at molecular chain termini.

The technology of producing a vinyl polymer having at least onecrosslinking silyl group at the molecular chain terminus, particularlysuch a (meth)acrylic polymer, is described in, Japanese KokokuPublication Hei-3-14068, Japanese Kokoku Publication Hei-4-55444 andJapanese Kokai Publication Hei-6-211922. However, since these areinvariably free radical polymerization processes utilizing said “chaintransfer agent technique”, the resulting polymer contains crosslinkingsilyl groups at molecular chain termini at a fairly high rate but hasthe drawback that the molecular weight distribution value, representedby Mw/Mn, is as large as 2 or more and, hence, the viscosity of thepolymer is high. Therefore, in order to provide a vinyl polymer having asmall molecular weight distribution value, hence a low viscosity value,and, yet, a high proportion of crosslinking silyl groups at molecularchain termini, the “living radical polymerization technique” mentionedhereinbefore is preferably employed.

Therefore, the vinyl polymer having at least one hydroxyl, halogen oralkenyl group for use in synthesizing said vinyl polymer having at leastone crosslinking silyl group preferably has such a functional group at amolecular chain terminus.

To produce a vinyl polymer having at least one said crosslinking silylgroup at the molecular chain terminus by the “atom transfer radicalpolymerization technique” which is the preferred variation of the“living radical polymerization” method, the initiator to be used ispreferably an organohalogen or sulfonyl halide compound having two ormore initiation points. The resulting vinyl polymer having at least onehighly reactive carbon-halogen bond at the molecular chain terminus canbe easily converted to the corresponding vinyl polymer having at leastone said crosslinking silyl group at the molecular chain terminus.

An organohalogen or sulfonyl halide compound having two or moreinitiation sites is not particularly restricted but includes thefollowing compounds, among others.o-, m- or p-XCH₂—C₆H₄—CH₂X, o-, m- or p-CH₃C(H)(X)—C₆H₄—C(H)(X) CH₃, o-,m- or p-(CH₃)₂C(X)—C₆H₄—C (X)(CH₃)₂(in the above formulas, C₆H₄ stands for a phenylene group; X representsa chlorine, bromine or iodine atom),RO₂C—C(H)(X)—(CH₂)_(n)—C(H)(X)—CO₂R,RO₂C—C(CH₃)(X)—(CH₂)_(n)—C(CH₃)(X)—CO₂R,RC(O)—C(H)(X)—(CH₂)—C(H)(X)—C(O)R, RC(O)—C(CH₃)(X)—(CH₂)—C(CH₃)(X)—C(O)R(in the above formulas, R represents an alkyl, aryl, or aralkyl groupcontaining up to 20 carbon atoms, n represents an integer of 0 to 2.0; Xrepresents a chlorine, bromine or iodine atom),XCH₂—C(O)—CH₂X, H₃C—C(H)(X)—C(O)—C(H)(X)—CH₃,(H₃C)₂C(X)—C(O)—C(X)(CH₃)₂, C₆H₅C(H)(X)—(CH₂)_(n)—C(H)(X) C₆H₅(in the above formulas, X represents a chlorine, bromine or iodine atom;n represents an integer of 0 to 20),XCH₂CO₂—(CH₂)_(n)—OCOCH₂X, CH₃C(H)(X)CO₂—(CH₂)_(n)—OCOC(H)(X) CH₃,(CH₃)₂C(X)CO₂—(CH₂)_(n)—OCOC (X)(CH₃)₂(in the above formulas, n represents an integer of 1 to 20)XCH₂C(O)C(O)CH₂X, CH₃C(H)(X)C(O)C(O)C(H)(X)CH₃,(CH₃)₂C(X)C(O)C(O)C(X)(CH₃)₂, o- m- or p-XCH₂CO₂—C₆₋₄—OCOCH₂X, o-, m- orp-CH₃C(H)(X)CO₂—C₆H₄—OCOC(H)(X)CH₃, o-, m- orp-(CH₃)₂C(X)CO₂—C₆H₄—OCOC(X)(CH₃)₂, o, m- or p-XSO₂—C₆H₄—SO₂X(in the above formulas, X represents a chlorine, bromine or iodine atom)These compounds can be used each independently or in a combination oftwo or more thereof.

For the production of a vinyl polymer having a crosslinking silyl groupat both molecular chain termini, not only the above-mentioned methodusing an organohalogen or sulfonyl halide compound having two initiationpoints as the initiator according to said atom transfer radicalpolymerization technique but also the method using an organohalogencompound containing a crosslinking silyl group (synthetic method [F])can be used with advantage.

The above organohalogen having a crosslinking silyl group is notparticularly restricted but includes compounds represented by thefollowing general formulas (19) and (20) among others.R¹⁵R¹⁶C(X)—R¹⁷—R¹⁸—C(H)(R¹⁹)CH₂—[Si(R¹)_(2-b)(Y)_(b)O]_(m)Si(R²)_(3-a)(Y)_(a)  (19)(wherein R¹, R² a, b, m, X and Y are as defined above; R¹⁵ and R¹⁶ maybe the same or different and each represents a hydrogen atom, an alkylgroup containing 1 to 20 carbon atoms, an aryl group containing 6 to 20carbon atoms or an aralkyl group containing 7 to 20 carbon atoms; R¹⁵and R¹⁶ may be linked to each other at the respective free termini; R¹⁷represents —C(O)O—, —C(O)—, or an o-, m- or p-phenylene group; R¹⁸represents a direct bond or a bivalent organic group of 1 to 10 carbonatoms which may optionally contain one or more ether linkages; R¹⁹represents a hydrogen atom, an alkyl group containing 1 to 10 carbonatoms, an aryl group containing 6 to 10 carbon atoms or an aralkyl groupcontaining 7 to 10 carbon atoms.(R²)_(3-a)(Y)_(a)Si—[OSi(R¹)_(2-b)(Y)_(b)]_(m)—CH₂—C(H)(R¹⁹)—R¹⁸—C(R¹⁵)(X)—R¹⁷—R¹⁶  (20)(wherein R¹, R², R¹⁵, R¹⁶, R¹⁷, R¹⁸, R¹⁹, a, b, m, X and Y are asdefined above)

When the “atom transfer radical polymerization” reaction is carried outusing the above-mentioned organohalogen having a crosslinking silylgroup as the initiator, there is obtained a vinyl polymer having thecrosslinking silyl group at one terminus and the highly reactivecarbon-halogen bond at the other terminus. By converting the terminalhalogen atom of this vinyl polymer to a crosslinking silyl-containingsubstituent group, for example by the technique described above, therecan be obtained a vinyl polymer having the crosslinking silyl group atboth molecular chain termini.

The above vinyl polymer having crosslinking silyl groups at both terminican also be produced by causing the halogen atoms of said vinyl polymerto undergo mutual coupling using a compound having at least two same ordifferent functional groups substitutable for the halogen atoms at saidtermini.

The above compound having at least two functional groups, same ordifferent, which are substitutable for the halogen atoms at said terminiis not particularly restricted but includes polyols, polyamines,polycarboxylic acids, polythiols and salts thereof; alkali metalsulfides; and so forth.

Further, when an organohalogen compound containing an alkenyl group isused as the initiator in said “atom transfer radical polymerization”,there is obtained a vinyl polymer having the alkenyl group at onemolecular chain terminus and the halogen atom at the other terminus. Byconverting the terminal halogen atom of this vinyl polymer to an alkenylgroup-containing substituent by the technique described hereinbefore,there can be obtained a vinyl polymer having the alkenyl group at bothmolecular chain termini. By converting these alkenyl groups tocrosslinking silyl groups, for example by the technique describedhereinbefore, there can be obtained a vinyl polymer having thecrosslinking silyl group at both molecular chain termini.

While the vinyl polymer having at least one said crosslinking silylgroup at the molecular chain terminus may be obtained by an arbitrarycombination of the processes described hereinbefore, the followingsynthetic processes A and B can be mentioned as typical processes.

Synthetic Process A

This process comprises

-   (1) a step of polymerizing a vinyl monomer by an atom transfer    radical polymerization technique to synthesize a halogen-terminated    vinyl polymer,-   (2) a step of reacting the halogen-terminated vinyl polymer obtained    in the above step (1) with an alkenyl group-containing oxyanion to    effect substitution for the halogen and thereby synthesize an    alkenyl-terminated vinyl polymer and-   (3) a step of adding a hydrosilane compound having a crosslinking    silyl group represented by the general formula (1) to the terminal    alkenyl group of the alkenyl-terminated vinyl polymer obtained in    the above step (2) to effect conversion to a substituent containing    said crosslinking silyl group.    Synthetic Process B

This process comprises

-   (1) a step of polymerizing a vinyl monomer by said living radical    polymerization technique to prepare a vinyl polymer,-   (2) a step of reacting the polymer further with a compound having at    least two sparingly polymerizable (low-polymerizability) alkenyl    groups to synthesize an alkenyl-terminated vinyl polymer, and-   (3) a step of adding a hydrosilane compound having a crosslinking    silyl group represented by the general formula (1) to the terminal    alkenyl group of the alkenyl-terminated vinyl polymer obtained in    the above step (2) to effect conversion to a substituent containing    said crosslinking silyl group.    [Photocurable Substance as (B) Component]

The photocurable substance for use as said (B) component used in thefirst aspect of the invention is a substance which, when exposed tolight, undergoes chemical change in molecular structure, hence physicalchanges such as curing, in a short period of time. While thephotocurable substance (B) in the first aspect of the invention may cureon exposure to light, a representative example is a substance which canbe cured by allowing it to stand in a sunlit interior environment (neara window) at room temperature for one day. As compounds of this type,many organic monomers, oligomers, resins and compositions containing anyof them are known. Thus, unsaturated acrylic compounds, poly(vinylcinnamate) compounds and azido resins, among others, can be mentioned byway of example.

The unsaturated acrylic compounds mentioned above include monomershaving an unsaturated group represented by the following general formula(21), the corresponding oligomers, and mixtures thereof.CH₂═CHR⁶CO(O)—  (21)wherein R⁶ is as defined hereinbefore.

More particularly, the unsaturated acrylic compounds include(meth)acrylic esters of low molecular alcohols such as ethylene glycol,glycerol, trimethylolpropane, pentaerythritol, neopentyl alcohol, etc.;(meth)acrylic esters of alcohols obtainable by the modification ofbisphenol A, acids such as isocyanuric acid, or said low molecularalcohols with ethylene oxide or propylene oxide; (meth)acrylic esters ofpolyether polyols each comprising a polyether as its main chain andhaving a hydroxyl group at its terminus, polymer polyols obtainable byradical polymerization of a vinyl monomer in a polyol having a polyetheras its main chain, polyester polyols each comprising a polyester as itsmain chain and having a hydroxyl group at its terminus, or polyols eachhaving a main chain comprised of a vinyl or (meth)acrylic polymer and ahydroxyl group within said main chain; epoxy acrylate oligomers eachobtainable by reacting bisphenol A or a novolac epoxy resin with(meth)acrylic acid; and urethane acrylate oligomers each having aurethane bond and a (meth)acrylate group within the molecular chain asobtainable by the reaction of a polyol, a polyisocyanate and ahydroxyl-containing (meth)acrylate, for instance.

The poly(vinyl cinnamate) compounds are photosensitive resins containinga cinnamoyl group as the photoreactive group and include poly(vinylalcohol)cinnamate and many derivatives of poly(vinyl cinnamate).

The azido resin is known as photosensitive resin containing an azidogroup as the photoreactive group and generally includes not only rubberphotosensitive liquids supplemented with azide compounds asphotosensitive agents but also the resins described in “PhotosensitiveResin” (Printing Society Press (Mar. 17, 1972), p. 93 et seq., 106 to117 et seq.). These can be used each independently or in admixture, orwhere necessary even with a sensitizer added.

Among the photocurable substances mentioned for the (B) component,unsaturated acrylic compounds are preferred from the standpoint of easeof handling.

The photocurable substance (B) is added preferably in a proportion of0.01 to 20 weight parts based on 100 weight parts of said vinyl polymerhaving a crosslinking silyl group (A1). At any addition amount below0.01 weight part, the effect of addition is small. If the amount of 20weight parts is exceeded, physical properties tend to be adverselyaffected. There are cases in which the effect is potentiated when asensitizer, such as a ketone and a nitro compound, and/or a promoter,such as an amine, is added.

[Optional Components]

In the curable composition according to the first aspect of theinvention, a curing catalyst or a curing agent is sometimes required.Moreover, according to the desired physical properties, variousauxiliary agents may be formulated.

<Curing Catalyst/Curing Agent>

The crosslinking silyl group-containing polymer crosslinks and cures asit undergoes siloxane bonding in the presence or absence of one of thevarious known condensation catalysts. As regards the properties of thecured product, a broad spectrum of products ranging from a rubberyproduct to a resinous product can be liberally produced by designing themolecular weight and backbone structure of the polymer judiciously.

The condensation catalyst which can be used includes various knownsilanol condensation catalysts, for example tetravalent tin compoundssuch as dibutyltin dilaurate, dibutyltin diacetate, dibutyltindiethylhexanolate, dibutyltin dioctoate, dibutyltin di(methyl maleate),dibutyltin di(ethyl maleate), dibutyltin di(butyl maleate), dibutyltindi(isooctyl maleate), dibutyltin di(tridecyl maleate), dibutyltindi(benzyl maleate), dibutyltin maleate, dioctyltin diacetate, dioctyltindistearate, dioctyltin dilaurate, dioctyltin di(ethyl maleate) anddioctyltin di(isooctyl maleate); titanic acid esters such as tetrabutyltitanate and tetrapropyl titanate; organoaluminum compounds such asaluminum trisacetylacetonate, aluminum tris(ethyl acetoacetate) anddiisopropoxyaluminum ethyl acetoacetate; chelate compounds such aszirconium tetraacetylacetonate and titanium tetraacectylacetonate; leadoctylate; amine compounds such as butylamine, octylamine, laurylamine,dibutylamine, monoethanolamine, diethanolamine, triethanolamine,diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine,benzylamine, diethylaminopropylamine, xylylenediamine,triethylenediamine, guanidine, diphenylguanidine,2,4,6-tris(dimethylaminomethyl)phenol, morpholine, N-methylmorpholine,2-ethyl-4-methylimidazole and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU),or salts of these amine compounds with carboxylic acids;low-molecular-weight polyamide resins obtained from an excess polyamineand a polybasic acid; reaction products from an excess polyamine and anepoxy compound; amino-containing silane coupling agents such asγ-aminopropyltrimethoxysilane andN-(β-aminoethyl)-aminopropylmethyldimethoxysilane; and, further, otheracidic and basic silanol condensation catalysts.

These catalysts can be used each independently or in a combination oftwo or more thereof. The formulating amount of the condensation catalystis preferably about 0.1 to 20 weight parts, more preferably 1 to 10weight parts, relative to 100 weight parts of the vinyl polymer havingat least one crosslinking silyl group (A1). When the formulating amountof the silanol condensation catalyst is below the above range, thecuring velocity may be decreased and the curing reaction may not proceedfully. On the other hand, when the formulating amount of the silanolcondensation catalyst exceeds the above range, local heating and foamingtend to take place in curing to make it impossible to obtain asatisfactory cured product. Moreover, since the pot life of thecomposition is too shortened, workability is adversely affected.

In the curable composition according to the first aspect of theinvention, a non-silanol group-containing silicon compound of thefollowing general formula (22) may be formulated for the purpose ofenhancing the condensation catalyst activity.R⁴⁹ _(a)Si(OR⁵⁰)_(4-a)  (22)(wherein R⁴⁹ and R⁵⁰ each independently represents a substituted orunsubstituted hydrocarbon group containing 1 to 20 carbon atoms; arepresents any of 0, 1, 2 and 3)

The silicon compound mentioned just above is not particularly restrictedbut is preferably the compound of the general formula (22) wherein R⁴⁹is an aryl group containing 6 to 20 carbon atoms, such as, for example,phenyltrimethoxysilane, phenylmethyldimethoxysilane,phenyldimethylmethoxysilane, diphenyldimethoxysilane,diphenyldiethoxysilane or triphenylmethoxysilane, for such compound ishighly capable of accelerating the curing reaction of the composition.Particularly, diphenyldimethoxysilane and diphenyldiethoxysilane aremost preferred from availability and cost points of view.

The formulating amount of said silicon compound is preferably about 0.01to 20 weight parts, more preferably 0.1 to 10 weight parts, based on 100weight parts of the vinyl polymer having at least one crosslinking silylgroup (A1). When the formulating amount of said silicon compound isbelow the above range, the accelerating effect on curing reaction tendsto be decreased. On the other hand, when the silicon compound isformulated in excess of the above range, the hardness and tensilestrength of the cured product tend to be decreased.

<Adhesion-Imparting Agent>

The composition of the invention may be supplemented with a silanecoupling agent and/or an adhesion-imparting agent other than silanecoupling agents. As examples of the silane coupling agent, there can bementioned isocyanato-containing silanes such asγ-isocyanatopropyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane,γ-isocyanatopropylmethyl-diethoxysilane,γ-isocyanatopropylmethyldimethoxysilane, etc.; amino-containing silanessuch as γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane,γ-(2-aminoethyl)aminopropyltrimethoxysilane,γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane,γ-(2-aminoethyl)aminopropylmethyldiethoxysilane,γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane,N-benzyl-γ-aminopropyltrimethoxysilane,N-vinylbenzyl-γ-aminopropyltriethoxysilane, etc.; mercapto-containingsilanes such as γ-mercaptopropyltrimethoxysilane,γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane,γ-mercaptopropylmethyldiethoxysilane, etc.; epoxy-containing silanessuch as γglycidoxypropyltrimethoxysilane,γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropylmethyldimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc.; carboxysilanes suchas β-carboxyethyltriethoxysilane,β-carboxyethylphenylbis(2-methoxyethoxy)silane,N-β-(carboxymethyl)aminoethyl-γ-aminopropyltrimethoxysilane, etc.; vinylunsaturated group-containing silanes such as vinyltrimethoxysilane,vinyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane,γ-acryloyloxypropylmethyltriethoxysilane, etc.; halogen-containingsilanes such as y-chloropropyltrimethoxysilane etc.; and isocyanuratesilanes such as tris(trimethoxysilyl)isocyanurate etc., among others.Moreover, modification products of these compounds, such asamino-modified silyl polymers, silylated amino polymers, unsaturatedaminosilane complexes, phenylamino-long-chain-alkylsilanes,aminosilylated silicones, silylated polyesters, etc. can also be used.

In practice of this invention, the silane coupling agent is generallyused in a proportion of 0.1 to 20 weight parts based on 100 weight partsof the vinyl polymer having a crosslinking silyl group (A1). Thepreferred proportion is 0.5 to 10 weight parts. As to the effect of thesilane coupling agent so added to the curable composition of theinvention, when the composition is applied to various adherends, namelyinorganic substrates such as glass, aluminum, stainless steel, zinc,copper, mortar, etc. or organic substrates such as poly(vinyl chloride),polyacrylic, polyester, polyethylene, polypropylene, polycarbonate andother resins, remarkable adhesion-improving effects appear both undernon-primer and under primer conditions. When used under non-primerconditions, the adhesion-improving effect to various adherends isparticularly pronounced.

The specific examples other than silane coupling agents are notparticularly restricted but include epoxy resins, phenolic resins,sulfur, alkyl titanates and aromatic polyisocyanates, among others.

The above adhesion-imparting agents may be used each independently or asa mixture of two or more species. Addition of any of theseadhesion-imparting agents contributes to the adhesion to variousadherends.

<Filler>

In the curable composition of the invention, there may be incorporatedvarious fillers as needed. As such fillers, there can be mentionedvarious reinforcing fillers such as woodmeal, pulp, cotton chips,asbestos, glass fibers, carbon fibers, mica flakes, walnut shell flour,rice hull flour, graphite, diatomaceous earth, clay, fumed silica,precipitated silica, crystalline silica, fused silica, dolomite, silicicanhydride, hydrous silicic acid and carbon black; fillers such ascalcium carbonate, magnesium carbonate, diatomaceous earth, calcinedclay, clay, talc, titanium dioxide, bentonite, organic bentonite, ferricoxide, finely divided aluminum, flint powder, zinc oxide, activated zincwhite, zinc dust and shirasu balloons; and fibrous fillers such asasbestos fibers, glass fibers and filaments and so forth. Preferred,among these fillers, are precipitated silica, fumed silica, crystallinesilica, fused silica, dolomite, carbon black, calcium carbonate,titanium dioxide and talc. For obtaining high-strength cured productsusing such fillers, there can be used a filler selected mainly fromamong fumed silica, precipitated silica, silicic anhydride, hydroussilicic acid, carbon black, surface-treated fine calcium carbonate,crystalline silica, fused silica, calcined clay, clay, activated zincwhite and so on. When cured products of low strength but high elongationare desired, there can be used a filler selected mainly from amongtitanium oxide, calcium carbonate, talc, ferric oxide, zinc oxide,shirasu balloons and the like. These fillers may be used singly or twoor more of them may be used in admixture. The addition amount of thefiller, when used, is not particularly restricted but is preferably 10to 1000 parts, more preferably 50 to 300 parts, based on 100 parts ofthe vinyl polymer (A1).

<Plasticizer>

In the curable composition of the invention, there may be incorporatedvarious plasticizers as needed. The plasticizer is not particularlyrestricted but, according to the physical property or appearancecharacteristic desired, use may be made of, for example, the following,either singly or in a combination of two or more: phthalic acid esterssuch as dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl)phthalateand butyl benzyl phthalate; nonaromatic dibasic acid esters such asdioctyl adipate, dioctyl sebacate, dibutyl sebacate and isodecylsuccinate; aliphatic esters such as butyl oleate and methylacetylricinolate; polyalkylene glycol esters such as diethylene glycoldibenzoate, triethylene glycol dibenzoate and pentaerythritol esters;phosphoric acid esters such as tricresyl phosphate and tributylphosphate; trimellitic acid esters; chlorinated paraffins; hydrocarbonoils such as alkyldiphenyls and partially hydrogenated terphenyl;process oils; polyethers such as polyethylene glycol and polypropyleneglycol; epoxy plasticizers such as epoxidized soybean oil and benzylepoxystearate; and polyester plasticizers; among others. The addition ofthese plasticizers is not always essential, however. It is also possibleto incorporate these plasticizers in the stage of polymer production.

<Solid-State Modifier>

The curable composition of the invention may be optionally supplementedwith a solid-state modifier for controlling the tensile characteristicsof the cured product.

The solid-state modifier is not particularly restricted but includesalkylalkoxysilanes such as methyltrimethoxysilane,dimethyldimethoxysilane, trimethylmethoxysilane andn-propyltrimethoxysilane; alkylisopropenoxysilanes such asdimethyldiisopropenoxysilane, methyltriisopropenoxysilane andγ-glycidoxypropylmethyldiisopropenoxysilane, functional group-containingalkoxysilanes such as γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane,vinyldimethylmethoxysilane, γ-aminopropyltrimethoxysilane,N-(β-aminoethyl)aminopropylmethyldimethoxysilane,γ-mercaptopropyltrimethoxysilane andγ-mercaptopropylmethyldimethoxysilane; silicone varnishes; andpolysiloxanes; among others. By using such a solid-state modifier, it ispossible to increase or decrease the hardness or increase the elongationon the occasion of curing of the composition of the invention. Thesesolid-state modifiers may be used each independently or in a combinationof two or more thereof.

<Thixotropic Agent (Antisagging Agent)>

The curable composition of the invention may be supplemented with athixotropic agent (antisagging agent) for prevention of sagging andimproved workability as needed.

The antisagging agent is not particularly restricted but includespolyamide waxes; hydrogenated castor oil derivatives; and metal soapssuch as calcium stearate, aluminum stearate and barium stearate, amongothers. These thixotropic agents (antisagging agents) may be used eachindependently or in a combination of two or more thereof.

Other Additives

For the purpose of adjusting various physical properties of the curablecomposition or cured product, the curable composition of the inventionmay be supplemented with various additives as necessary. As typicaladditives, there can be mentioned flame retardants, curabilitymodulators, aging inhibitors, radical terminators, ultravioletabsorbers, metal ion deactivator, ozone degradation inhibitors, lightstabilizers, phosphorus-type peroxide decomposers, lubricants, pigments,blowing agents, and photocurable resin. These various additives may beused singly or in a combination of two or more species.

Specific examples of those additives are described in the specificationsof Japanese Kokoku Publication Hei-4-69659, Japanese Kokoku PublicationHei-7-108928, Japanese Kokai Publication Sho-63-254149 and JapaneseKokai Publication Sho-64-22904.

The curable composition of the present invention can be prepared as aone-component system such that all the components are premixed andsealed and, after application or installation, let the whole be cured insitu by atmospheric moisture or as a two-component system such that acuring agent comprising the curing catalyst, filler, plasticizer, water,etc. and a polymer composition are admixed prior to application.

[Uses]

Though not restricted, the curable composition of this invention findsapplication in a broad spectrum of uses, for example sealants such asarchitectural elastic sealants, composite-glass sealants,electric/electronic component materials such as a solar cell backsealant, etc., electrical insulating materials such as conductor/cableinsulation sheaths, etc., adhesives, self-adhesives, elastic adhesives,coatings, powder coatings, coating dopes, foams, electric/electronicpotting materials, film, gaskets, potting compounds, various moldingcompounds, rust-preventive, water-proofing sealants for wire-reinforcedglass or laminated glass edges (cut edges) and so on.

<<The Second Aspect of the Invention>>

The curable composition according to the second aspect of the presentinvention is now described in detail.

The curable composition according to the second aspect of the inventioncomprises (A2) a vinyl polymer having a crosslinking-silyl group and (C)an air oxidation-curable substance. The vinyl polymer for use as thecomponent (A2) is identical with the vinyl polymer (A1) so fardescribed.

[Air Oxidation-Curable Substance for (C) Component]

The air oxidation-curable substance for use as the (C) component in thesecond aspect of the invention is a compound containing an unsaturatedgroup capable of being crosslinked and cured by the atmospheric oxygen.The air oxidation-curable substance (C) for use in this second aspect ofthe invention is a substance which undergoes curing on contact with air,more specifically a substance having the property to cure by reactingwith oxygen in the air. A representative air oxidation-curable substancecan be cured, for example by allowing it to stand in an interiorenvironment at room temperature for one day.

The air oxidation-curable substance includes drying oils such as tungoil, linseed oil, etc.; various alkyd resins obtainable by modifyingsuch drying oils, drying oil-modified acrylic polymers, epoxy resins orsilicone resins; polymers or copolymers of C₅₋₈ dienes such as1,2-polybutadiene, 1,4-polybutadiene, etc., and various modificationproducts e.g. maleated, boiled oil-modified, etc.) of said polymers orcopolymers. Of these substances, tung oil, liquid species of dienepolymers (liquid diene polymers) and modification products thereof areparticularly preferred.

As said liquid diene polymers, there can be mentioned liquid polymersobtainable by polymerizing or copolymerizing such diene compounds asbutadiene, chloroprene, isoprene, 1,3-pentadiene, etc.; NBR, SBR andother polymers obtainable by copolymerizing said diene compounds with acopolymerizable monomer such as acrylonitrile, styrene and the like inthe ratio such that a diene monomer is mainly shared and variousmodification products thereof (maleated, boiled oil-modified, etc.).These polymers can be used each independently or in a combination of twoor more thereof. Among these liquid diene compounds, liquidpolybutadiene is particularly preferred.

The air oxidation-curable substance may be used each independently or ina combination of two or more thereof. Further, an enhanced effect may attimes be obtained when such an air oxidation-curable substance is usedin combination with a catalyst promoting an oxidation-curing reaction ora metallic dryer. As examples of said catalyst or metallic dryer, therecan be mentioned various metal salts such as cobalt naphthenate, leadnaphthenate, zirconium naphthenate, cobalt octanoate, zirconiumoctanoate, etc. and amine compounds.

The air oxidation-curable substance (C) is added preferably in aproportion of 0.01 to 20 weight parts to 100 weight parts of the vinylpolymer having a crosslinking silyl group (A2). At an addition amountbelow 0.01 weight parts, the effect of addition is small. Over 20 weightparts, adverse effects on physical properties may be encountered.

The curable composition according to the second aspect of the inventionmay be supplemented with various optional components similar to thosementioned for the first aspect of the invention.

The curable composition according to the second aspect of the presentinvention can be prepared as a one-component system such that all thecomponents are premixed and sealed and, after application, let it becured in situ by atmospheric moisture or as a two-component system suchthat a curing agent comprising the curing catalyst, filler, plasticizer,water, etc. and a polymer composition are admixed prior to application.

Though not restricted, the curable composition according to the secondaspect of the invention finds application in a broad spectrum of uses,for example sealants such as architectural elastic sealants,composite-glass sealants, electric/electronic materials such as a solarcell back sealant, etc., electrical insulating materials such asconductor/cable insulation sheaths, etc., adhesives, self-adhesives,elastic adhesives, coatings, powder coatings, coating dopes, foams,electric/electronic potting materials, film, gaskets, potting compounds,various molding compounds, rust-preventive, water-proofing sealants forwire-reinforced glass or laminated glass edges (cut edges) and so on.

<The Third Aspect of the Invention>

The curable composition according to the third aspect of the inventionis now described in detail.

The curable composition according to the third aspect of the inventioncomprises (A3) a crosslinking functional group-containing vinyl polymerand (D) a high molecular plasticizer.

[The Vinyl Polymer for (A3) Component]

The main chain and method for production of the vinyl polymer (A3) arethe same as those described for the vinyl polymer (A1).

<Crosslinking Functional Group>

The crosslinking functional group of the vinyl polymer (A3) is notparticularly restricted but is preferably a crosslinking silyl group, analkenyl group, a hydroxyl group, an amino group, a polymerizablecarbon-carbon double bond, or an epoxy group. These crosslinkingfunctional groups can be selectively used according to the intendedapplication/object.

Number of Crosslinking Functional Groups

The crosslinking functional group should exist in the number of at leastone on the average per molecule of polymer (A3) When this crosslinkingfunctional groups is less than one per molecule, no sufficiently curedproduct can be obtained. The average number of crosslinking functionalgroups per molecule necessary to give a satisfactory cured product isgenerally 1.1 to 5, preferably 1.2 to 4, more preferably 1.3 to 3.

Position of the Crosslinking Functional Group

When the curable composition according to the third aspect of theinvention is required to give a cured product having rubber-likeproperties in particular, it is preferable that at least onecrosslinking functional group is present at the molecular chainterminus, for the molecular mass between crosslinking points, which hasconsiderable bearings on rubber elasticity, can then be large. Morepreferably, all crosslinking functional groups are located at molecularchain termini.

The technology of producing a vinyl polymer having at least onecrosslinking functional group at the molecular chain terminus,particularly such a (meth)acrylic polymer, is described in, JapaneseKokoku Publication Hei-3-14068, Japanese Kokoku Publication Hei-4-55444and Japanese Kokai Publication Hei-6-211922. However, since these areinvariably free radical polymerization processes utilizing said “chaintransfer agent technique”, the resulting polymer has crosslinkingfunctional groups at molecular chain termini at a fairly high rate buthas the drawback that the molecular weight distribution value,represented by Mw/Mn, is as large as 2 or more and, hence, the viscosityof the polymer is high. Therefore, in order to provide a vinyl polymerhaving a small molecular weight distribution value, hence a lowviscosity value, and, yet, a high proportion of crosslinking functionalgroups at molecular chain termini, the “living radical polymerizationtechnique” mentioned hereinbefore is preferably employed.

These functional groups are explained below. The crosslinking silylgroup is preferably the one described for the first aspect of theinvention.

Alkenyl Group

The alkenyl group in this invention is not particularly restricted butis preferably one represented by the following general formula (23).H₂C═C(R¹¹)—  (23)(wherein R¹¹ represents a hydrogen atom or a hydrocarbon groupcontaining 1 to 20 carbon atoms)

Referring to the above general formula (23), R¹¹ is a hydrogen atom or ahydrocarbon group containing 1 to 20 carbon atoms such as, for example,the following.—(CH₂)_(n)—CH₃, —CH(CH₃)—(CH₂)_(n)—CH₃, —CH(CH₂CH₃)—(CH₂)_(n)—CH₃,CH(CH₂CH₃)₂, —C(CH₃)₂—(CH₂)_(n)—CH₃, —C(CH₃)(CH₂CH₃)—(CH₂)_(n)—CH₃,—C₆H₅, —C₆H₅(CH₃), —C₆H₅(CH₃)₂—(CH₂)_(n)—C₆H₅, —(CH₂)_(n)—C₆H₅(CH₃) and—(CH₂)_(n)—C₆H₅(CH₃)₂(n is an integer of 0 or more; the total number of carbon atoms in eachgroup is up to 20 at the maximum)

The preferred, among them, is a hydrogen atom.

Furthermore, it is preferable, though not essential, that the alkenylgroup of polymer (A3) is not in an activated state due to a carbonyl,alkenyl or aromatic ring conjugated to its carbon-carbon double bond.

The mode of linkage between the alkenyl group and the main chain is notparticularly restricted but they are preferably linked to each otherthrough a carbon-carbon bond, an ester linkage, an ester linkage, acarbonate bond, an amido linkage, or a urethane linkage.

Amino Group

The amino group in this invention is not particularly restricted but mayfor example be a group represented by the formula—NR¹² ₂(wherein R¹² represents a hydrogen atom or a univalent organic groupcontaining 1 to 20 carbon atoms; the two R¹² groups may be the same ordifferent and may be joined to each other at the respective free terminito form a cyclic structure). It may also be an ammonium salt asrepresented by the formula:—(NR¹² ₃)⁺X⁻(wherein R¹² represents a hydrogen atom or a univalent organic groupcontaining 1 to 20 carbon atoms; the two R¹² groups may be the same ordifferent and may be joined to each other at the respective free terminito form a cyclic structure; X⁻ represents a counter anion)

In the above formulas, R¹² is a hydrogen atom or a univalent organicgroup containing 1 to 20 carbon atoms. More particularly, it may forexample be a hydrogen atom, an alkyl group containing 1 to 20 carbonatoms, an aryl group containing 6 to 20 carbon atoms, or an aralkylgroup containing 7 to 20 carbon atoms. The two R¹² groups may be thesame or different. Further, these groups may be joined to each other atthe respective free termini to form a cyclic structure.

Polymerizable Carbon-carbon Double Bond

The group having a polymerizable carbon-carbon double bond is preferablya group of the following general formula (24):—OC(O)C(R¹³)═CH₂  (24)(wherein R¹³ represents a hydrogen atom or a univalent organic groupcontaining 1 to 20 carbon atoms), more preferably a group of the aboveformula wherein R¹³ represents a hydrogen atom or a methyl group.

Referring to the above general formula (24), R¹³ is not particularlyrestricted but includes, among others, the following species:

—H, —CH₃, —CH₂CH₃, —(CH₂)_(n)CH₃ (n represents an integer of 2 to 19)—C₆H₅, —CH₂OH, and —CN. Preferred is —H or —CH₃.

<Method for Introduction of the Crosslinking Functional Group>

The method of introducing a functional group into the vinyl polymer isdescribed below, although this method is not an exclusive choice.

It is to be understood that when a crosslinking silyl group, an alkenylgroup or a hydroxyl group is to be introduced by terminal functionalgroup transformation, the processes described hereinbefore can beutilized with advantage.

Epoxy Group

The vinyl polymer having an epoxy group in accordance with thisinvention can be produced for example by the process comprising thefollowing steps:

-   (1) a step of polymerizing a vinyl monomer by a living radical    polymerization technique to obtain a vinyl polymer and-   (2) a step of reacting the polymer with a compound having both an    epoxy group and an ethylenically unsaturated group.

An alternative process comprises reacting an allyl alcohol at theterminal stage of atom transfer radical polymerization and, thereafter,effecting an epoxy-cyclization utilizing a hydroxyl group and a halogengroup.

Amino Group

A process for producing a vinyl polymer having an amino group at atleast one terminus of its main chain comprises the following steps:

-   (1) a step of preparing a vinyl polymer having a halogen group at at    least one terminus of its main chain to obtain a vinyl polymer and-   (2) a step of reacting an amino-containing compound with the polymer    to convert the terminal halogen to an amino-containing substituent.

The amino-containing substituent mentioned above is not particularlyrestricted but may for example be a group of the general formula (25):—O—R²⁶—NR¹² ₂  (25)(wherein R²⁶ represents a C₁₋₂₀ bivalent organic group optionallycontaining one or more ether or ester linkages; R¹² represents ahydrogen atom or a univalent organic group containing 1 to 20 carbonatoms and the two R¹² groups may be the same or different and may bejointed to each other at the respective free termini to form a cyclicstructure).

Referring to the above general formula (25), R²⁶ is a C₁₋₂₀ bivalentorganic group optionally containing one or more ether or ester linkages,such as, for example, an alkylene group containing 1 to 20 carbon atoms,an arylene group containing 6 to 20 carbon atom or an aralkylene groupcontaining 7 to 20 carbon atoms, preferably a group represented by theformula:—C₆H₄—R²⁷—(wherein C₆H₄ stands for a phenylene group; R²⁷ represents a direct bondor a bivalent organic group containing 1 to 14 carbon atoms andoptionally containing one or more ether or ester linkages) or a group ofthe formula:—C(O)—R²⁸—(wherein R²⁸ represents a direct bond or a bivalent organic groupcontaining 1 to 19 carbon atoms and optionally containing one or moreether or ester linkages)

An amino group can be introduced into the terminus of a vinyl polymer byconverting the terminal halogen of a vinyl polymer. The method for thissubstitution is not particularly restricted but, from the standpoint ofthe ease of control, it is preferable to use a nucleophilic substitutionreaction using an amino-containing compound as a nucleophilic agent. Assuch a nucleophilic agent, there can be mentioned a compound having botha hydroxyl group and an amino group as, for example, represented by thegeneral formula (26):HO—R²⁶—NR¹² ₂  (26)(wherein R²⁶ represents a C₁₋₂₀ bivalent organic group optionallycontaining one or more ether or ester linkages; R¹² represents ahydrogen atom or a univalent organic group containing 1 to 20 carbonatoms and the two R¹² groups may be the same or different and may bejoined to each other at the respective free termini to form a cyclicstructure).

Referring to the above general formula (26), R²⁶ is a C₁₋₂₀ bivalentorganic group optionally containing one or more ether or ester linkagesand may for example be an alkylene group containing 1 to 20 carbonatoms, an arylene group containing 6 to 20 carbon atoms, or anaralkylene group containing 7 to 20 carbon atoms. The preferred, amongsuch compounds having both a hydroxyl group and an amino group, areaminophenol compounds wherein R²⁶ represents—C₆H₄—R²⁷(wherein C₆H₄ stands for a phenylene group; R²⁷ represents a direct bondor a C₁₋₁₄ bivalent organic group optionally containing one or moreether or ester linkages) and amino acid compounds of the formula:—C(O)—R²⁸—(wherein R²⁸ represents a direct bond or a C₁₋₁₉ bivalent organic groupoptionally containing one or more ether or ester linkages).

As specific such compounds, there can be mentioned ethanolamine; o, m,p-aminophenol; o, m, p-NH₂—C₆H₄—CO₂H; glycine, alanine and aminobutanoicacid, among others.

A compound having both an amino group and an oxyanion may also be usedas said nucleophilic agent. Such compound is not particularly restrictedbut includes compounds represented by the general formula (27), amongothers:M⁺O⁻—R²⁶—NR¹² ₂  (27)(wherein R²⁶ represents a C₁₋₁₀ bivalent organic group optionallycontaining one or more ether or ester linkages; R¹² represents ahydrogen atom or a univalent organic group containing 1 to 20 carbonatoms and the two R¹² groups may be the same or different and may bejoined to each other at the respective free termini to form a cyclicstructure; M⁺ represents an alkali metal ion or a quaternary ammoniumion).

Referring to the above general formula (27), M⁺ represents the countercation to the oxyanion and is an alkali metal ion or a quaternaryammonium ion. As specific examples of the alkali metal ion, there may bementioned the lithium ion, sodium ion and potassium ion. Preferred issodium ion or potassium ion. As the quaternary ammonium ion, there maybe mentioned the tetramethylammonium ion, tetraethylammonium ion,trimethylbenzylammonium ion, trimethyldodecylammonium ion,tetrabutylammonium ion and dimethylpiperidinium ion.

Among the above compounds having both an amino group and an oxyanion,salts of aminophenols represented by the general formula (28) and saltsof amino acids represented by the general formula (29) are preferredbecause of the ease of control of the substitution reaction as well asfrom availability points of view.M⁺O⁻C₆H₄—R²⁷—NR¹² ₂  (28)M⁺O⁻—C(O)—R²⁸—NR¹² ₂  (29)(wherein C₆H₄ stands for a phenylene group; R² represents a direct bondor a C₁₋₁₄ bivalent organic group optionally containing one or moreether or ester linkages; R³ represents a direct bond or a C₁₋₁₉ bivalentorganic group optionally containing one or more ether or ester linkages;R¹² represents a hydrogen atom or a C₁₋₂₀ univalent organic group andthe two R¹² groups may be the same or different and may be jointed toeach other at the respective free termini to form a cyclic structure; M⁺has the same meaning as defined hereinabove)

The oxyanion-containing compound represented by the general formulas(27) to (29) can each be obtained by reacting a compound of the generalformula (26) with a basic compound.

As the basic compound, various compounds can be selectively employed.Thus, for example, sodium methoxide, potassium methoxide, lithiummethoxide, sodium ethoxide, potassium ethoxide, lithium ethoxide, sodiumtert-butoxide, potassium tert-butoxide, sodium carbonate, potassiumcarbonate, lithium carbonate, sodium hydrogen carbonate, sodiumhydroxide, potassium hydroxide, sodium hydride, potassium hydride,methyllithium, ethyllithium, n-butyllithium, tert-butyllithium, lithiumdiisopropylamide and lithium hexamethyldisilazide, among others, can bementioned. The amount of use of said base is not particularly restrictedbut, based on said precursor, may range from 0.5 to 5 equivalents,preferably 0.8 to 1.2 equivalents.

As the solvent to be used in reacting the above precursor with a basiccompound, there may be mentioned hydrocarbon solvents such as benzeneand toluene; ether solvents such as diethyl ether and tetrahydrofuran;halogenated hydrocarbon solvents such as methylene chloride andchloroform; ketone solvents such as acetone, methyl ethyl ketone andmethyl isobutyl ketone; alcohol solvents such as methanol, ethanol,propanol, isopropyl alcohol, n-butyl alcohol and tert-butyl alcohol;nitrile solvents such as acetonitrile, propionitrile and benzonitrile;ester solvents such as ethyl acetate and butyl acetate; carbonatesolvents such as ethylene carbonate and propylene carbonate; amidesolvents such as dimethylformamide and dimethylacetamide; sulfoxidesolvents such as dimethyl sulfoxide; and so on. These may be used singlyor two or more of them may be used in admixture.

The oxyanion-containing compound in which M⁺ is a quaternary ammoniumion can be obtained by preparing a compound having an alkali metal ionfor M⁺ and reacting this compound with a quaternary ammonium halide. Asexamples of the quaternary ammonium halide, there may be mentionedtetramethylammonium halides, tetraethylammonium halides,trimethylbenzylammonium halides, trimethyldodecylammonium halides andtetrabutylammonium halides.

A variety of solvents can be used for the substitution (conversion)reaction of the terminal halogen of the polymer. As the solvents, theremay be mentioned hydrocarbon solvents such as benzene and toluene; ethersolvents such as diethyl ether and tetrahydrofuran; halogenatedhydrocarbon solvents such as methylene chloride and chloroform; ketonesolvents such as acetone, methyl ethyl ketone and methyl isobutylketone; alcohol solvents such as methanol, ethanol, propanol, isopropylalcohol, n-butyl alcohol and tert-butyl alcohol; nitrile solvents suchas acetonitrile, propionitrile and benzonitrile; ester solvents such asethyl acetate and butyl acetate; carbonate solvents such as ethylenecarbonate and propylene carbonate; amide solvents such asdimethylformamide and dimethylacetamide; and sulfoxide solvents such asdimethyl sulfoxide; among others. These may be used each independentlyor in a combination of two or more thereof.

The reaction can be carried out in the temperature range of 0 to 150° C.The amount of use of the amino group-containing compound is notparticularly restricted but may be 1 to 5 equivalents, preferably 1 to1.2 equivalents, relative to the terminal halogen of the polymer.

For accelerating the nucleophilic substitution reaction, a basiccompound may be added to the reaction mixture. Such a basic compoundincludes not only the compounds already mentioned herein but alsoalkylamines such as trimethylamine, triethylamine, tributylamine, etc.;polyamines such as tetramethylethylenediamine,pentamethyldiethylenetriamine, etc.; and pyridine compounds such aspyridine and picoline, among others.

When the amino group of the amino group-containing compound for use inthe nucleophilic substitution reaction may affect the nucleophilicsubstitution reaction, the amino group is preferably protected with asuitable substituent group. The substituent group includesbenzyloxycarbonyl, tert-butoxycarbonyl and 9-fluorenylmethoxycarbonyl,among others.

There may also be mentioned a process which comprises replacing thehalogen terminus of a vinyl polymer with an azide anion and reducing thesame with, for example, LAH.

Polymerizable Carbon-Carbon Double Bond

The technology of introducing a polymerizable carbon-carbon double bondinto a vinyl polymer includes but is not limited to the followingprocesses.

-   {circle around (1)} The process which comprises substituting the    halogen group of a vinyl polymer with a compound having a    radical-polymerizable carbon-carbon double bond. As a specific    example, there can be mentioned a process which comprises reacting a    vinyl polymer represented by the following general formula (30) with    a compound represented by the following formula (31).    —CR²⁹R³⁰X  (30)    (wherein R²⁹ and R³⁰ each represents a group bound to the    ethylenically unsaturated group of a vinyl monomer; X represents a    chlorine, bromine or iodine atom)    M⁺⁻OC(O)C(R¹³)═CH₂  (31)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; M⁺ represents an alkali metal ion    or a quaternary ammonium ion]-   {circle around (2)} The process which comprises reacting a    hydroxyl-containing vinyl polymer with a compound of the following    general formula (32)    XC(O)C(R¹³)═CH₂  (32)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; X represents a chlorine or bromine    atom or a hydroxyl group]-   {circle around (3)} The process which comprises reacting a    hydroxyl-containing vinyl polymer with a diisocyanate compound and    causing the residual isocyanato group to react with a compound of    the following general formula (33).    HO—R³¹—OC(O)C(R¹³)═CH₂  (33)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; R³¹ represents a bivalent organic    group containing 2 to 20 carbon atoms]

The above processes are respectively described in detail below.

The process {circle around (1)} is now described in detail.

-   (1) The process which comprises reacting a vinyl polymer represented    by the following general formula (30) with a compound represented by    the following formula (31).    —CR²⁹R³⁰X  (30)    (wherein R²⁹ and R³⁰ each represents a group bound to the    ethylenically unsaturated group of a vinyl monomer; X represents a    chlorine, bromine or iodine atom)    M⁺⁻OC(O)C(R¹³)═CH₂  (31)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; M⁺ represents an alkali metal ion    or a quaternary ammonium ion]

The vinyl polymer having a terminal structure of the general formula(30) can be produced by the above-mentioned technology for polymerizinga vinyl monomer using an organohalogen compound or a sulfonyl halidecompound as the initiator and a transition metal complex as the catalystor the above-mentioned technology for polymerizing a vinyl monomer usinga halogen compound as the chain transfer agent, preferably by the formermethod.

The compound represented by the general formula (31) is not particularlyrestricted. As specific examples of R¹³, there can be mentioned —H,—CH₃, —CH₂CH₃, —(CH₂)_(n)CH₃ (n represents an integer of 2 to 19),—C₆H₅, —CH₂OH, —CN, etc., and preferred, among these, is —H or —CH₃.

M⁺ represents the counter cation to the oxyanion and is an alkali metalion such as lithium ion, sodium ion and potassium ion and a quaternaryammonium ion. As the quaternary ammonium ion, there may be mentioned thetetramethylammonium ion, tetraethylammonium ion, tetrabenzylammoniumion, trimethyldodecylammonium ion, tetrabutylammonium ion anddimethylpiperidinium ion. Preferred is sodium ion or potassium ion.

The amount of use of the oxyanion of the general formula (31) relativeto the halogen group of the general formula (30) is preferably 1 to 5equivalents, more preferably 1.0 to 1.2 equivalents. The solvent for usein carrying out this reaction is not particularly restricted but,because the reaction is a nucleophilic substitution reaction, ispreferably a polar solvent such as, for example, tetrahydrofuran,dioxane, diethyl ether, acetone, dimethyl sulfoxide, dimethylformamide,dimethylacetamide, hexamethylphosphoric triamide, acetonitrile and soon. The reaction temperature is not particularly restricted butgenerally the reaction is conducted at 0 to 150° C., preferably at roomtemperature to 100° C. for maintaining the polymeric terminal group.

The process (2) mentioned above is now described.

-   {circle around (2)} The process which comprises reacting a    hydroxyl-containing vinyl polymer with a compound of the general    formula (32).    XC(O)C(R¹³)═CH₂  (32)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; X represents a chlorine or bromine    atom or a hydroxyl group]

The compound represented by the general formula (32) is not particularlyrestricted. As specific examples of R¹³, there can be mentioned —H,—CH₃, —CH₂CH₃, —(CH₂)_(n)CH₃ (n represents an integer of 2 to 19),—C₆H₅, —CH₂OH, —CN, etc.; preferred, among these, is —H or —CH₃.

A vinyl polymer having a hydroxyl group, preferably at its terminus, canbe produced by the above-mentioned technology for polymerizing a vinylmonomer using an organohalogen compound or a sulfonyl halide compound asthe initiator and a transition metal complex as the catalyst or theabove-mentioned technology for polymerizing a vinyl monomer using ahydroxyl group-containing compound as the chain transfer agent,preferably by the former method. The specific technique which can beused for producing a hydroxyl-containing vinyl polymer is not restrictedbut includes the following processes in addition to the above-mentionedprocesses.

-   (a) The process which comprises subjecting a compound having both a    polymerizable alkenyl group and a hydroxyl group as represented by    the following general formula (34) to reaction as a second monomer    in synthesizing the vinyl polymer by living radical polymerization:    H₂C═C(R³²)—R³³—R³⁴—OH  (34)    wherein R³² represents an organic group containing 1 to 20 carbon    atoms, preferably a hydrogen atom or a methyl group, and may be the    same or different within the molecule; R³³ represents —C(O)O— (an    ester group) or an o-, m- or p-phenylene group; R³⁴ represents a    direct bond or a bivalent organic group containing 1 to 20 carbon    atoms which may optionally contain one or more ether linkages. The    compound in which R³³ represents an ester group is a (meth)acrylate    compound and the compound in which R³³ represents a phenylene group    is a styrenic compound.

The timing of reacting the compound having both a polymerizable alkenylgroup and a hydroxyl group per molecule is not particularly restrictedbut, when the expression of rubber-like properties are expected, thecompound is subjected to reaction as a second monomer preferably at thefinal stage of the polymerization reaction or after completion of thereaction of the predetermined vinyl monomer.

-   (b) The process which comprises subjecting a compound having a    sparingly polymerizable alkenyl group and a hydroxyl group per    molecule to reaction as a second monomer at the final stage of the    polymerization reaction or after completion of the reaction of the    predetermined vinyl monomer in synthesizing the vinyl polymer by    living radical polymerization.

Such compound is not particularly restricted but includes, among others,compounds represented by the general formula (35)H₂C═C(R³²)—R³⁵—OH  (35)wherein R³² is as defined above and R³⁵ represents a bivalent C₁₋₂₀organic group optionally containing one or more ether linkages.

The compound represented by the above general formula (35) is notparticularly restricted but alkenyl alcohols such as 10-undecenol,5-hexenol and allyl alcohol are preferred from availability points ofview.

-   (c) The process disclosed in Japanese Kokai Publication    Hei-04-132706, for instance, which comprises terminally introducing    a hydroxyl group by hydrolyzing the halogen of a vinyl polymer    having at least one carbon-halogen bond, represented by the general    formula (30), as obtained by atom transfer radical polymerization or    reacting the halogen with a hydroxyl-containing compound.-   (d) The process which comprises reacting a vinyl polymer having at    least one carbon-halogen bond, represented by the general formula    (30), as obtained by atom transfer radical polymerization with a    stabilized, hydroxyl-containing carbanion such as the one    represented by the general formula (36) to thereby effect    substitution for the halogen:    M⁺C⁻(R³⁶).(R³⁷)—R³⁵—OH  (36)    wherein R³⁵ is as defined above; R³⁶ and R³⁷ each represents an    electron-withdrawing group stabilizing the carbanion C or one of    them represents such an electron-withdrawing group and the other    represents a hydrogen atom, an alkyl group containing 1˜10 carbon    atoms or a phenyl group. As the electron-withdrawing group R³⁶    and/or R³⁷, there may be mentioned —CO₂R (ester group) —C(O)R (keto    group), —CON(R₂) (amide group), —COSR (thioester group), —CN    (nitrile group) and —NO₂ (nitro group), among others. The    substituent R is an alkyl group containing 1 to 20 carbon atoms, an    aryl group containing 6 to 20 carbon atoms or an aralkyl group    containing 7 to 20 carbon atoms and preferably is an alkyl group    containing 1 to 10 carbon atoms or a phenyl group. Particularly    preferred as R and R³⁷ are —CO₂R, —C(O)R and —CN.-   (e) The process which comprises reacting a vinyl polymer having at    least one carbon-halogen bond, represented by the general formula    (30), as obtained by atom transfer radical polymerization with an    elemental metal, such as zinc, or an organometal compound and then    reacting the thus-prepared enolate anion with an aldehyde or ketone.-   (f) The process which comprises reacting a vinyl polymer having at    least one terminal halogen atom, preferably a halogen represented by    the general formula (30), with a hydroxyl-containing oxyanion    represented by the general formula (37) shown below or the like or a    hydroxyl-containing carboxylate anion represented by the general    formula (38) shown below or the like to thereby substitute a    hydroxyl-containing substituent for the halogen:    HO—R³⁵—O⁻M⁺  (37)    wherein R³⁵ and M⁺ are as defined above;    HO—R³⁵—C(O)O⁻M⁺  (38)    wherein R³⁵ and M⁺ are as defined above.

In the practice of the invention, when any halogen is not directlyinvolved in introducing a hydroxyl group, as in the processes (a) and(b), the process (b) is comparatively more preferred since the controlis easier. In cases where the hydroxyl group introduction is effected byconverting the halogen of a vinyl polymer having at least onecarbon-halogen bond, as in the processes (c) to (f), the process (f) iscomparatively more preferred since the control is easier.

The process {circle around (3)} is now described.

-   {circle around (3)} The process which comprises reacting a    hydroxyl-containing vinyl polymer with a diisocyanate compound and    causing the residual isocyanato group to react with a compound of    the general formula (39).    HO—R³¹—OC(O)C(R¹³)═CH₂  (39)    [wherein R¹³ represents a hydrogen atom or an organic group    containing 1 to 20 carbon atoms; R³¹ represents a bivalent organic    group containing 2 to 20 carbon atoms]

The compound represented by the general formula (39) is not particularlyrestricted. As specific examples of R¹³, there can be mentioned —H,—CH₃, —CH₂CH₃, —(CH₂)_(n)CH₃ (n represents an integer of 2˜19), —C₆H₅,—CH₂OH, —CN, etc.; the preferred, among these, is —H or —CH₃. As aspecific compound, there can be mentioned 2-hydroxypropyl methacrylate.

The hydroxyl-terminated vinyl polymer is as described above.

The diisocyanate compound for use is not particularly restricted and maybe any of the hitherto-known isocyanates, such as toluylenediisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethyldiisocyanate, xylylene diisocyanate, m-xylylene diisocyanate,1,5-naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate,hydrogenated toluylene diisocyanate, hydrogenated xylylene diisocyanate,isophorone diisocyanate, and so on. These may be used each independentlyor two or more of them may be used in combination. Blocked isocyanatesmay also be used.

As the polyfunctional isocyanate compound (b) for insuring an improvedweather resistance, it is preferable to use an aromatic ring-freediisocyanate compound such as hexamethylene diisocyanate andhydrogenated diphenylmethane diisocyanate.

[High Molecular Plasticizer for (D) Component]

The high molecular plasticizer (D) for use in the third aspect of theinvention has a number average molecular weight of 500 to 15000. Byadding this high molecular plasticizer, not only the viscosity and slumpof the curable composition and the mechanical characteristics, such astensile strength and elongation, of the cured product obtainable fromsaid composition can be liberally controlled but, compared with the useof a low molecular plasticizer not containing a polymer component in themolecule, the initial physical properties can be maintained for anextended time period and the drying properties of the alkyd coat appliedto the cured product (i.e. coatability) can be improved. It is to beunderstood that the high molecular plasticizer in the third aspect ofthe invention is not a plasticizer having a group of the above generalformula (1).

While the number average molecular weight of said high molecularplasticizer is 500 to 15000 as mentioned above, the preferred range is800 to 10000 and the more preferred range is 1000 to 8000. When themolecular weight is too low, the plasticizer is caused to leach out byheat and rainwater so that the initial physical properties cannot bemaintained long and the alkyd coating coatability of the cured productcannot be improved. On the other hand, when the molecular weight is toohigh, the viscosity is increased to detract from workability.

As examples of said high molecular plasticizer, there can be mentionedvinyl polymers obtainable by polymerizing said vinyl monomers by varioustechniques; polyester plasticizers obtainable from dibasic acids such assebacic acid, adipic acid, azelaic acid, phthalic acid, etc. anddihydric alcohols such as ethylene glycol, diethylene glycol,triethylene glycol, propylene glycol, dipropylene glycol, etc.;polyethers such as polyethylene glycol, polypropylene glycol,polytetramethylene glycol, etc. and derivatives obtainable by convertingthe hydroxyl groups of such polyether polyols to ester, ether or othergroups; polystyrenes such as polystyrene, poly(α-methylstyrene), etc.;polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile,polychloroprene, and paraffin chloride, among others.

Among these high molecular plasticizers, the preferred are plasticizerscompatible with the crosslinking functional group-containing polymer(A3). From the standpoint of compatibility, weather resistance and heatresistance, in particular, vinyl polymers are preferred. The preferred,among said vinyl polymers, are (meth)acrylic polymers, with acrylicpolymers being particularly preferred. As the mode of synthesizing suchpolymers, living radical polymerization is preferred because the methodis conducive to a narrow molecular weight distribution and a lowviscosity, with the atom transfer radical polymerization technique beingparticularly preferred.

The molecular weight distribution of the high molecular plasticizer (D)is not particularly restricted but is preferably narrow enough, namelyless than 1.8. It is more preferably not more than 1.7, still morepreferably not more than 1.6, further more preferably not more than 1.5,particularly not more than 1.4, most preferably not more than 1.3.

The high molecular plasticizers mentioned above may be used eachindependently or in a combination of two or more thereof. Wherenecessary, these plasticizers can be used in combination with lowmolecular plasticizers within the range not adversely affecting thephysical properties.

The amount of use of said high molecular plasticizer (D) is 5 to 150weight parts, preferably 10 to 120 weight parts, more preferably 20 to100 weight parts, based on 100 weight parts of the vinyl polymer havingat least one crosslinking functional group as (A3) component. At anamount below 5 weight parts, the effect expected of a plasticizer is notexpressed. If the amount exceeds 150 weight parts, the mechanicalstrength of the cured product will not be as high as desired.

Depending on the kind of crosslinking functional group, the curablecomposition according to the third aspect of the invention calls foraddition of a curing catalyst and curing agent. Moreover, depending onthe desired physical properties, a variety of additives may also beformulated.

<Curing Catalyst/Curing Agent>

In the Case of a Crosslinking Silyl Group

The crosslinking silyl group-containing polymer crosslinks and cures asit undergoes siloxane bonding in the presence or absence of one of theknown condensation catalysts. As regards the properties of the curedproduct, a broad spectrum of products ranging from a rubbery one to aresinous one can be liberally obtained according to the molecular weightand backbone structure of the polymer. As such a condensation catalyst,the catalysts mentioned hereinbefore can be mentioned.

These catalysts can be used each independently or in a combination oftwo or more thereof. The formulating amount of the condensation catalystis preferably about 0.1 to 20 weight parts, more preferably 1 to 10weight parts, relative to 100 weight parts of the vinyl polymer havingat least one crosslinking silyl group (A3). When the formulating amountof the silanol condensation catalyst is below the above range, thecuring velocity may be decreased so that the curing reaction may notproceed fully. On the other hand, when the formulating amount of thesilanol condensation catalyst exceeds the above range, local heating andfoaming tend to take place in curing to make it impossible to obtain asatisfactory cured product. Moreover, since the pot life of thecomposition is shortened, workability is adversely affected.

In the curable composition of the invention, a silanol group-freesilicon compound of the following general formula (40) may be formulatedfor the purpose of enhancing the condensation catalyst activity:R⁴⁹ _(a)Si(OR⁵⁰)_(4-a)  (40)(wherein R⁴⁹ and R⁵⁰ each independently represents a substituted orunsubstituted C₁₋₂₀ hydrocarbon group; a represents any of 0, 1, 2 and3).

The silicon compound mentioned just above is not particularly restrictedbut is preferably the compound of the general formula (40) wherein R⁴⁹is an aryl group containing 6 to 20 carbon atoms, such as, for example,phenyltrimethoxysilane, phenylmethyldimethoxysilane,phenyldimethylmethoxysilane, diphenyldimethoxysilane,diphenyldiethoxysilane and triphenylmethoxysilane, for such compound hasthe accelerating effect on curing reaction of the composition.Particularly, diphenyldimethoxysilane and diphenyldiethoxysilane aremost preferred from availability and cost points of view.

The formulating amount of said silicon compound is preferably about 0.01to 20 weight parts, more preferably 0.1 to 10 weight parts, based on 100weight parts of the vinyl polymer having at least one crosslinking silylgroup (A3). When the formulating amount is below the above range, theaccelerating effect on curing reaction tends to be decreased. On theother hand, when the silicon compound is formulated in excess of theabove range, the hardness and tensile strength of the cured product tendto be decreased.

In the Case of an Alkenyl Group

For the crosslinking through an alkenyl group, the crosslinking reactionis preferably, but not essentially, effected by hydrosilylation using ahydrosilyl group-containing compound as the curing agent together with ahydrosilylation catalyst.

The hydrosilyl group-containing compound is not particularly restrictedinasmuch as it is a hydrosilyl compound capable of curing an alkenylgroup-containing polymer through crosslinking and various compounds canbe utilized. Thus, for example, there can be employed linearpolysiloxanes represented by the general formula (41) or (42);R⁵¹ ₃SiO—[Si(R⁵¹)₂O]_(a)—[Si(H)(R⁵²)O]_(b)—[Si(R⁵²)(R⁵³)O]_(c)—SiR⁵¹₃  (41)R⁵¹ ₂SiO—[Si(R⁵¹)₂O]_(a)—[Si(H)(R⁵²)O]_(b)—[Si(R⁵²)(R⁵³)O]_(c)—SiR⁵¹₂H  (42)(In the above formulas, R⁵¹ and R⁵² each represents an alkyl groupcontaining 1 to 6 carbon atoms or a phenyl group; R⁵³ represents analkyl or aralkyl group containing up to 10 carbon atoms; a represents aninteger of 0≦a≦100; b represents an integer of 2≦b≦100; c represents aninteger of 0≦c≦100) and cyclic siloxanes represented by the generalformula (43)

(wherein R⁵⁴ and R⁵⁵ each represents an alkyl group containing 1 to 6carbon atoms or a phenyl group; R⁵⁶ represents an alkyl or aralkyl groupcontaining up to 10 carbon atoms; d represents an integer of 0≦d≦8; erepresents an integer of 2≦e≦10; f represents an integer of 0≦f≦8; therelation of 3≦d+e+f≦10 is satisfied)

These compounds can be used each independently or two or more of themmay be used in admixture. Among the above siloxanes, the compoundspreferred from the standpoint of compatibility with (meth)acrylicpolymers are phenyl-containing linear siloxanes represented by thefollowing general formula (44) or (45) and cyclic siloxanes representedby the general formula (46) or (47).(CH₃)₃SiO—[Si(H)(CH₃)O]_(g)—[Si(C₆H₅)O]_(h)—Si(CH₃)₃  (44)(CH₃)₃SiO—[Si(H)(CH₃)O]_(g)—[Si(CH₃){CH₂C(H)(R⁵⁷)C₆H₅}O]_(h)—Si(CH₃)₃  (45)(In the above formulas, R⁵⁷ represents a hydrogen atom or a methylgroup; g represents an integer of 2≦g≦100; h represents an integer of0≦h≦100; C₆H₅ stands for a phenyl group)

(In the above formulas, R⁵⁷ represents a hydrogen atom or a methylgroup; i represents an integer of 2≦i≦10 and j represents an integer of0≦j≦8, with the condition of 3≦i+j≦10 satisfied; C₆H₅ stands for aphenyl group)

Also usable as the hydrosilyl group-containing compound is a compoundprepared by addition-reacting a hydrosilyl group-containing compoundrepresented by any of the general formulas (41) through (47) with a lowmolecular compound containing two or more alkenyl groups per molecule insuch a manner that part of the hydrosilyl functional group will remainafter the reaction. As said compound containing 2 or more alkenylgroups, various compounds can be used. As examples, there can bementioned hydrocarbon compounds such as 1,4-pentadiene, 1,5-hexadiene,1,6-heptadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, etc.; ethercompounds such as 0,0′-diallylbisphenol A, 3,3′-diallylbisphenol A,etc.; ester compounds such as diallyl phthalate, diallyl isophthalate,triallyl trimellitate, tetraallyl pyromellitate, etc.; and carbonatecompounds such as diethylene glycol diallylcarbonate and so on.

The objective compound can be obtained by adding said alkenylgroup-containing compound slowly dropwise to an excess of saidhydrosilyl group-containing compound represented by any of the generalformulas (41) through (47) in the presence of a hydrosilylationcatalyst. From the standpoint of availability of the starting compound,ease of removal of the excess siloxane, and compatibility with the (A)component polymer, the following compounds are particularly preferred.

(n represents an integer of 2 to 4; m represents an integer of 5 to 10)

The polymer and curing agent can be admixed in an arbitrary ratio but,from curability points of view, the alkenyl-to-hydrosilyl molar ratio ispreferably in the range of 5 to 0.2, more preferably 2.5 to 0.4. If themolar ratio exceeds 5, curing will be insufficient to give only a tackycured product of low strength. If the ratio is smaller than 0.2, manyactive hydrosilyl groups remain unreacted after curing to cause cracksand voids, failing to provide a cured product of uniform strength.

The curing reaction between the polymer and curing agent proceeds asthey are admixed and heated but in order to expedite the reaction, ahydrosilylation catalyst may be added. The hydrosilylation catalyst forsuch use is not particularly restricted but includes a radicalinitiator, such as an organic peroxide or an azo compound, and atransition metal catalyst.

The radical initiator is not particularly restricted but includesdialkyl peroxides such as di-tert-butyl peroxide,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane,2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, dicumyl peroxide,tert-butylcumyl peroxide andα,α′-bis(tert-butyl-peroxy)isopropylbenzene, diacyl peroxides such asbenzoyl peroxide, p-chlorobenzoyl peroxide, m-chlorobenzoyl peroxide,2,4-dichlorobenzoyl peroxide and lauroyl peroxide, peresters such astert-butyl perbenzoate, peroxydicarbonates such as diisopropylperoxydicarbonate and di-2-ethylhexyl peroxy-dicarbonate, andperoxyketals such as 1,1-di(tert-butylperoxy)cyclohexane and1,1-di(tert-butylperoxy) 3,3,5-trimethylcyclohexane, among others.

The transition metal catalyst is not particularly restricted butincludes elemental platinum, solid platinum dispersed on a matrix suchas alumina, silica and carbon black, chloroplatinic acid, complexes ofchloroplatinic acid with alcohols, aldehydes, ketones or the like,platinum-olefin complexes and platinum(0)-divinyltetramethyldisiloxanecomplex, among others. As examples of the catalyst other than platinumcompounds, there may be mentioned RhCl(PPh₃)₃, RhCl₃, RuCl₃, IrCl₃,FeCl₃, AlCl₃, PdCl₂.H₂O, NiCl₂, TiCl₄, etc. These catalysts may be usedsingly or two or more of them may be used combinedly. The amount of thecatalyst is not particularly restricted but recommendably is within therange of 10⁻¹ to 10⁻⁸ mole, preferably within the range of 10⁻³ to 10⁻⁶mole, per mole of the alkenyl group of the vinyl polymer (A3). When itis less than 10⁻⁸ mole, the curing may not proceed to a sufficientextent. Since the hydrosilylation catalyst is expensive, it isrecommendable that this catalyst is not used in an amount exceeding 10⁻¹mole.

The curing temperature is not particularly restricted but is generallyat 0° C. to 100° C., preferably 30° C. to 150° C., more preferably at80° C. to 150° C.

In the Case of a Hydroxyl Group

The hydroxyl group-containing polymer can be cured uniformly by using acompound having two or more functional groups capable of reacting withthe hydroxyl functional group as a curing agent. The curing agentincludes polyisocyanates having two or more isocyanato groups in themolecule, methylolated melamine and its alkyl ethers or aminoplastresins such as low-condensation products thereof, polycarboxylic acidsand halides thereof, among others. In producing a cured product usingsuch a curing agent, a curing catalyst suited to each can be used.

In the Case of an Amino Group

The amino group-containing polymer can be cured uniformly by using acompound having two or more functional groups capable of reacting withthe amino function as a curing agent. As examples of the curing agent,there can be mentioned polyisocyanate compounds having two or moreisocyanate groups in the molecule, methylolated melamine and its alkylethers or aminoplast resins such as low-condensation products thereof,polycarboxylic acids and halides thereof, among others. In producing acured product using such a curing agent, a curing catalyst suited toeach can be used.

In the Case of an Epoxy Group

The curing agent for the epoxy group-containing polymer is notparticularly restricted but includes aliphatic amines, alicyclic amines,aromatic amines; acid anhydrides; polyamides; imidazoles; amineimides;urea; melamine and its derivatives; polyamine salts; phenolic resins;polymercaptans, polysulfides; and photo- or UV-curing agents such asaromatic diazonium salts, diallyliodonium salts, triallylsulfoniumsalts, triallylselenium-salts and so on.

In the Case of a Polymerizable Carbon-Carbon Double Bond

The polymer having a polymerizable carbon-carbon double bond can becrosslinked by polymerizing said polymerizable carbon-carbon doublebond. The crosslinking method includes curing by actinic radiation andcuring by heat. In the case of an actinic radiation-curable composition,the photopolymerization initiator is preferably a photoradical initiatoror a photoanion initiator. In a heat-curable composition, the thermalpolymerization initiator is preferably a member selected from the groupconsisting of azo initiators, peroxides, persulfates and redoxinitiators.

These crosslinking reactions are now described in detail.

For causing crosslinking of the polymer having a polymerizablecarbon-carbon double bond, other polymerizable monomer(s) and/oroligomers and various additives may also be formulated according to theobjective. As such polymerizable monomers and/or oligomers, it ispreferable to use monomers and/or oligomers having radical-polymerizablegroups or monomers and/or oligomers having anion-polymerizable groups.As the radical-polymerizable groups, there can be mentioned an acrylicfunctional group such as (meth)acryloyl, styryl, acrylonitrile, vinylester, N-vinylpyrrolidone, acrylamide, conjugated diene, vinyl ketone,and vinyl chloride groups, among others. Among these, those having a(meth)acryloyl group are preferred. The anion-polymerizable groupsinclude (meth)acryloyl, styryl, acrylonitrile, N-vinylpyrrolidone,acrylamide, conjugated diene, and vinyl ketone groups, among others.Among these, those having an acrylic functional group are preferred.

As examples of such monomers, there can be mentioned (meth)acrylatemonomers, cyclic acrylates, N-vinylpyrrolidone, styrenic monomers,acrylonitrile, N-vinylpyrrolidone, acrylamide monomers, conjugated dienemonomers and vinyl ketone monomers, among others. The (meth)acrylatemonomers include n-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,isooctyl (meth)acrylate, isononyl(meth)acrylate, and compounds of thefollowing formulas.

The styrenic monomer includes styrene, α-methylstyrene, etc.; theacrylamide monomer includes acrylamide, N,N-dimethylacrylamide, etc.;the conjugated diene monomer includes butadiene, isoprene, etc.; and thevinyl ketone monomer includes methyl vinyl ketone, among others.

The polyfunctional monomer includes neopentyl glycol polypropoxydiacrylate, trimethylolpropane polyethoxy triacrylate, bisphenol Fpolyethoxy diacrylate, bisphenol A polyethoxy diacrylate,dipentaerythritol polyhexanolide hexaacrylate,tris(hydroxyethyl)isocyanurate polyhexanolide triacrylate,tricyclodecanedimethylol diacrylate,2-(2-acryloyloxy-1,1-dimethyl)-5-ethyl-5-acryloyloxymethyl-1,3-dioxane,tetrabromobisphenol A diethoxy diacrylate, 4,4-dimercaptodiphenylsulfide dimethacrylate, polytetraethylene glycol diacrylate,1,9-nonanediol diacrylate and ditrimethylolpropane tetraacrylate, amongothers.

The oligomer includes epoxy acrylate resins such as bisphenol A epoxyacrylate resin, phenol novolac epoxy acrylate resin, cresol novolacepoxy acrylate resin, etc., COOH-modified epoxy acrylate resins,urethane-acrylate resins obtainable by reacting a hydroxyl-containing(meth)acrylate [e.g. hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, orpentaerythritol triacrylate] with the urethane resin obtained from apolyol (e.g. polytetramethylene glycol, ethylene glycol-adipic acidpolyester diol, å-caprolactone-modified polyester diols, polypropyleneglycol, polyethylene glycol, polycarbonate diols, hydroxy-terminatedhydrogenated polyisoprene, hydroxy-terminated polybutadiene,hydroxy-terminated polyisobutylene, etc.) and an organic isocyanate(e.g. tolylene diisocyanate, isophorone diisocyanate, diphenylmethanediisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, etc.),and resins synthesized by introducing (meth)acryloyl groups into saidpolyols through ester linkages, and polyester acrylate resins.

These monomers and oligomers are selected with reference to thepolymerization initiator and curing conditions to be used.

The number average molecular weight of the acrylic functionalgroup-containing monomer and/or oligomer is preferably not larger than2000 and, from a compatibility point of view, is more preferably notlarger than 1000.

The crosslinking of the polymer having a polymerizable carbon-carbondouble bond is preferably effected by means of an actinic radiation suchas UV light and an electron beam.

For the crosslinking by an actinic radiation, a photopolymerizationinitiator is preferably formulated.

The photopolymerization initiator that can be used in this invention isnot particularly restricted but is preferably a photoradical initiatoror a photoanionic initiator, more preferably a photoradical initiator.For example, there can be mentioned acetophenone, propiophenone,benzophenone, xanthol, fluorene, benzaldehyde, anthraquinone,triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone,3-pentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone,4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone,4-methylbenzophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone,4-chloro-4′-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone,3-chloro-8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butylether, bis(4-dimethylaminophenyl)ketone, benzyl methoxy ketal and2-chlorothioxanthone. These initiators can be used alone or incombination with other compounds. As specific examples, there can bementioned combinations with an amine such as diethanolmethylamine,dimethylethanolamine, triethanolamine or the like, said combinationsfurther including an iodonium salt such as diphenyliodonium chloride,and combinations with a pigment, e.g. methylene blue, and an amine.

As the near-infrared photopolymerization initiator, cationic dyesabsorbing in the near infrared (IR) region of the spectrum can be used.As such near IR-absorbing cationic dyes, it is preferable to use thenear-1R-absorbing cationic dye-borate anion complexes which are excitedby photoenergy within the range of 650 to 1500 nm as disclosed inJapanese Kokai Publication Hei-3-111402 and Japanese Kokai PublicationHei-5-194619, among others, and it is still more advantageous to use aboron-type sensitizer in combination.

The addition amount of the photopolymerization initiator need only bejust enough to slightly photofunctionalize the system and is notparticularly restricted but is preferably 0.001 to 10 weight parts basedon 100 weight parts of the polymer component of the composition.

The mode of curing the actinic radiation-curable composition of theinvention is not particularly restricted, but depending on theproperties of the particular photopolymerization initiator, ahigh-pressure mercury vapor lamp, a low-pressure mercury vapor lamp, anelectron beam irradiation apparatus, a halogen lamp, a light-emittingdiode and a semiconductor laser, among others, can be selectivelyemployed as the light source.

The crosslinking of said polymer having a polymerizable carbon-carbondouble bond is preferably effected by means of heat.

For crosslinking by actinic radiation, a thermal polymerizationinitiator is preferably formulated. The thermal polymerization initiatorthat can be used in this invention is not particularly restricted butincludes azo compounds, peroxides, persulfates and redox initiators.

Suitable azo initiators include but are not limited to2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33),2,2′-azobis(2-amidinopropane)dihydrochloride (VAZO 50),2,2′-azobis(2,4-dimethylvaleronitrile) (VAZO 52),2,2′-azobis(isobutyronitrile) (VAZO 64),2,2′-azobis-2-methylbutyronitrile (VAZO 67),1,1-azobis(1-cyclohexanecarbonitrile) (VAZO 88) (all available fromDuPont Chemical), 2,2′-azobis(2-cyclopropylpropionitrile), and2,2′-azobis(methyl isobutyrate) (V-601) (available from Wako PureChemical Ind.), among others.

Suitable peroxide initiators include but are not limited to benzoylperoxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetylperoxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate (Perkadox16S) (available from Akzo Nobel), di(2-ethylhexyl)peroxydicarbonate,t-butyl peroxypivalate (Lupersol 11) (available from Elf Atochem),t-butyl peroxy-2-ethyl hexanoate (Trigonox 21-C50) (available from AkzoNobel), and dicumyl peroxide.

Suitable persulfate initiators include but are not limited to potassiumpersulfate, sodium persulfate and ammonium persulfate.

Suitable redox (oxidation-reduction) initiators include but are notlimited to combinations of said persulfate initiators with a reducingagent such as sodium hydrogen metasulfite and sodium hydrogen sulfite;organic peroxide-tertiary amine systems, e.g. benzoylperoxide-dimethylaniline; and organic hydroperoxide-transition metalsystems, e.g. cumene hydroperoxide-cobalt naphthenate.

Other initiators include but are not limited to pinacols such astetraphenyl-1,1,2,2-ethanediol.

Preferred thermal radical initiators can be selected from among azoinitiators and peroxide initiators. Still more preferred are2,2′-azobis(methyl isobutyrate), t-butyl peroxypivalate,di(4-t-butylcyclohexyl)peroxydicarbonate, and a mixture thereof.

The thermal polymerization initiator to be used in the present inventionshould be added in a catalytically effective amount which is notparticularly restricted but is typically about 0.01 to 5 weight parts,preferably about 0.025 to 2 weight parts, based on 100 weight parts ofthe polymer having an acrylic functional group in at least one terminalposition and said other mixture of monomers and oligomers. When aninitiator mixture is used, the total amount of initiators in the mixturecorresponds to the amount of any such initiator used singly.

The method of curing the heat-curable composition of the invention isnot particularly restricted. The curing temperature is dependent on thethermal initiator, polymer (A3) and specific compounds to be added but,for all practical purposes, is preferably in the range of 50° C. to 250°C., more preferably 70 C to 200 C. The cure time, which depends on thepolymerization initiator, monomer, solvent, reaction temperature andother variables, is generally in the range of 1 minute to 10 hours.

In addition, the same adhesion-imparting agent, filler, solid-statemodifier, thixotropic agent (antisagging agent) and other additives asmentioned for the first aspect of the invention can be similarlyformulated.

The curable composition according to the third aspect of the inventioncan be prepared as a one-component system such that all the componentsare premixed and sealed and, after application, let the whole be curedin situ by atmospheric moisture or as a two-component system such that acuring agent comprising the curing catalyst, filler, plasticizer, water,etc. and a polymer composition are admixed prior to application.

The curable composition according to the third aspect of the inventionfinds application in a broad spectrum of uses, for example sealants suchas architectural elastic sealants, composite-glass sealants,electric/electronic materials such as a solar cell back sealant, etc.,electrical insulating materials such as conductor/cable insulationsheaths, etc., adhesives, self-adhesives, elastic adhesives, coatings,powder coatings, coating dopes, foams, electric/electronic pottingmaterials, film, gaskets, potting compounds, various molding compounds,rust-preventive, water-proofing sealants for wire-reinforced glass orlaminated glass edges (cut edges) and so on.

<<The Fourth Aspect of the Invention>>

The curable composition according to the fourth aspect of the inventionis now described.

The curable composition according to the fourth aspect of the inventioncomprises (A4) a vinyl polymer having a crosslinking silyl group and (E)a reactive plasticizer (generally called “reactive diluent”, too).

[The Vinyl Polymer for (A4) Component]

The (A4) component according to the fourth aspect of the invention is avinyl polymer having not less than 1.1 of crosslinking silyl grouprepresented by the general formula (1) given hereinabove on the averageper molecule, which crosslinks and cures by siloxane bonding. Thegeneral formula (1) representing the crosslinking silyl group in the(A4) component is identical to the general formula (1) representing thecrosslinking silyl group in the (A1) component in the first aspect ofthe invention.

When the average number of crosslinking silyl groups of the generalformula (1) per molecule is less than 1.1, a sufficiently cured productcannot be obtained. The average number, per molecule, of crosslinkingsilyl groups of the general formula (1) which is necessary to provide asufficiently cured product is generally 1.1 to 5, preferably 1.2 to 4,more preferably 1.3 to 3.

The monomer constituting the main chain of the polymer is notparticularly restricted as far as it is a vinyl monomer, and includesthose mentioned for the first aspect of the invention.

From the standpoint of physical properties, the vinyl polymer having notless than 1.1 of the defined crosslinking silyl groups on the average ispreferably a (meth)acrylic polymer synthesized by using a (meth)acrylicmonomer, among said monomers, in a proportion of not less than 40 weight%. The still more preferred is an acrylic polymer synthesized by usingan acrylic monomer, among said various monomers, in a proportion of notless than 30 weight %.

The number average molecular weight of the vinyl polymer having not lessthan 1.1 of said crosslinking silyl groups on the average is notparticularly restricted but is preferably within the range of 500 to100000. At a molecular weight less than 500, the intrinsiccharacteristics of a vinyl polymer are hardly manifested and, at above100000, handling may become difficult in some instances.

The molecular weight distribution, namely the ratio (Mw/Mn) of weightaverage molecular weight (Mw) to number average molecular weight (Mn),of the vinyl polymer having not less than 1.1 of said crosslinking silylgroups on the average is not particularly restricted. For facilitatinghandling by controlling the viscosity of the curable composition at alow amount while securing sufficient cured physical properties, however,a narrow molecular weight distribution is preferred. The molecularweight distribution value is preferably less than 1.8, more preferablynot more than 1.7, still more preferably not more than 1.6, yet morepreferably not more than 1.5, still more preferably not more than 1.4,most preferably not more than 1.3. Most prevalently, the molecularweight distribution is determined by gel permeation chromatography(GPC). The number average molecular weight and so on can be determinedon the polystyrene equivalent basis using chloroform or THF as themobile phase and polystyrene gel columns as columns.

The method of synthesizing a vinyl polymer having not less than 1.1 ofsaid crosslinking silyl groups on the average per molecule is notparticularly restricted but includes various methods describedhereinabove for the first aspect of the invention. Among them, asynthetic procedure utilizing a living radical polymerization techniqueis preferred and a procedure utilizing the atom transfer radicalpolymerization technique is more preferred. As typical productionmethods, the same processes as said synthetic methods A and B for the(A1) component can be mentioned.

When the curable composition according to the fourth aspect of theinvention is required to give a cured product having rubber-likeproperties in particular, it is preferable that said crosslinking silylgroup is present in the number of not less than 1.1 on the average atthe molecular chain terminus, for the molecular mass betweencrosslinking points, which has considerable bearings on rubberelasticity, can then be large. More preferably, all crosslinking silylgroups are located at molecular chain termini.

[The Reactive Plasticizer for (E) Component]

The reactive plasticizer for use as the (E) component in the fourthaspect of the invention, which is predominantly composed of a vinylpolymer having not more than one of crosslinking silyl group representedby the general formula (1) exclusively at one molecular chain terminuson the average per molecule, that is to say a vinyl polymer having saidcrosslinking silyl group of the general formula (1) at one terminus onlyand not having said crosslinking silyl group of the general formula (1)at the other terminus. By adding this reactive plasticizer (E), not onlythe workability with the curable composition in both the formulationstage and the application stage can be improved but also a goodflexibility can be imparted to the cured product and the adverse effectof plasticizer migration will be suppressed.

While the number of crosslinking silyl groups in the (E) component inthe fourth aspect of the invention is defined as being “not more thanone on the average”, this definition takes into account the impurityhaving no crosslinking silyl group. For example, even when the vinylpolymer having one crosslinking silyl group is produced by the methoddescribed hereinafter, it is still difficult to avoid by-production of avinyl polymer not having the crosslinking silyl group. Furthermore, itis difficult to selectively eliminate the fraction not having thecrosslinking silyl group from the reactive plasticizer as a polymer(unlike the elimination of low-molecular compounds) Therefore, thenumber of crosslinking silyl groups in the reactive plasticizer is notmore than one on the average. Furthermore, when the (E) component in thefourth aspect of the invention is identified by analysis, the number ofcrosslinking silyl groups in the reactive plasticizer may sometimes befound only as the average value, so that the average value in thepresent invention is used for the crosslinking silyl group.

The reactive plasticizer (E) in the fourth aspect of the invention has acrosslinking silyl group only at one molecular chain terminus so that,unlike the vinyl polymer (A4), it is substantially incapable of forminga crosslink by itself. However, when cured along with the (A4)component, one molecular chain terminus provided with the crosslinkingsilyl group reacts with the crosslinking silyl group of the (A4)component and, as a consequence, the reactive plasticizer (E) is takenup in the cured product. However, since the (E) component has amolecular chain terminus not participating in crosslinking, it functionsas a plasticizer. As the (E) component is taken up in the cured productthrough crosslinking and, hence, is not substantially extracted out intothe environment such as water, oil, solvent or air, the aging ofphysical properties and environmental contamination due to a migrationof the plasticizer which tends to occur often with the conventionalplasticizer are lessened.

The preferred crosslinking silyl group of the reactive plasticizer (E)is the same as the silyl group of the component (A4).

As the vinyl monomer constituting the main chain of said reactiveplasticizer (E), any of the vinyl monomers which can be used for said(A1) component can be used and these can be used each independently orin a combination of two or more thereof. However, since the (E)component should be a vinyl polymer having a crosslinking silyl group atonly one molecular chain terminus, monomers containing crosslinkingsilyl groups cannot be used except when a crosslinking silyl group is tobe introduced into the molecular chain terminus.

The reactive plasticizer (E) is preferably a (meth)acrylic polymerobtainable by a synthetic process using a (meth)acrylic monomer, amongsaid various monomers, in a proportion of not less than 40 weight %.Furthermore, said reactive plasticizer is preferably an acrylic polymerobtained by a synthetic process using an acrylic monomer, among saidvarious monomers, in a proportion of not less than 30 weight %.

The reactive plasticizer (E) mentioned above is preferably a plasticizerwhich is liquid in the formulation stage or application stage of thecurable composition and, moreover, is preferably lower in viscosity thanthe vinyl polymer having a crosslinking silyl group (A4). Moreover, itis preferable that, when these components are admixed, either ahomogeneous state or a microscopic phase-separation state be assumed.

The number average molecular weight of said reactive plasticizer (E) ispreferably 500 to 15000, more preferably 800 to 10000. The still morepreferred molecular weight range is 1000 to 8000. When the molecularweight of (E) is less than 500, the effect expected of a reactiveplasticizer is not expressed. When it exceeds 15000, theviscosity-lowering effect is not expressed.

The molecular weight distribution of the reactive plasticizer (E) is notparticularly restricted but, in terms of viscosity-lowering effect, ispreferably narrow enough, i.e. less than 1.8. The distribution value ismore preferably not more than 1.7, still more preferably not more than1.6, more preferably not more than 1.5, particularly not more than 1.4,most preferably not more than 1.3.

The vinyl polymer (E) having not more than one of crosslinking silylgroup of the general formula (1) on the average can be produced byvarious alternative methods. Thus, the following methods [G] to [K],though not limited thereto, can be mentioned.

-   [G] A method which comprises adding a hydrosilane compound having a    crosslinking silyl group to a vinyl polymer having an alkenyl group    only at one molecular chain terminus.

This production method [G] is similar to the production method [A] forthe (A1) component but different in that a vinyl polymer having analkenyl group only at one molecular chain terminus is employed. Thevinyl polymer having an alkenyl group only at one molecular chainterminus can be prepared by the alternative processes [G-a] to [G-j] tobe described hereinafter, although these processes are not exclusivechoices.

-   [H] A method which comprises reacting a vinyl polymer having a    hydroxyl group only at one molecular chain terminus with a compound    having both a crosslinking silyl group and a functional group    capable of reacting with a hydroxyl group, such as an isocyanato    group.

The above production method [H] is similar to the production method [B]for the (A1) component but different only in that a vinyl polymer havinga hydroxyl group only at one molecular chain terminus is used as thesubstrate polymer. The vinyl polymer having a hydroxyl group only at onemolecular chain terminus can be produced by the processes [H-a] to [H-f]to be described hereinafter, although these processes are not exclusivechoices available.

-   [I] A method for synthesizing a vinyl polymer by a living radical    polymerization technique using an initiator having one initiation    point, which comprises reacting a compound having both a    polymerizable alkenyl group and a crosslinking silyl group in the    terminal stage of the polymerization reaction or after completion of    the reaction of the predetermined vinyl monomer.

As the compound having both a polymerizable alkenyl group and acrosslinking silyl group for use in the above production method [I],there can be mentioned compounds represented by the above generalformula (17). The initiator having one initiation point for use in theliving radical polymerization will be described later herein.

-   [J] A method which comprises subjecting a vinyl monomer to radical    polymerization using a crosslinking silyl group-containing chain    transfer agent.

The crosslinking silyl group-containing chain transfer agent for use inthe above method [J] for synthesis is not particularly restricted as faras it is capable of introducing a crosslinking silyl group into only onemolecular chain terminus. Thus, for example, there can be mentioned thecrosslinking silyl group-containing mercaptans disclosed in JapaneseKokoku Publication Hei-3-14068, for instance, namely3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,3-mercaptopropylmethyldimethoxysilane, etc., and ths crosslinking silylgroup-containing hydrosilanes which are disclosed in Japanese KokokuPublication Hei-4-55444, for instance. Furthermore, radical initiatorshaving a crosslining silyl group may also be employed.

-   [K] A method which comprises reacting a vinyl polymer having a    highly reactive carbon-halogen bond at only one molecular chain    terminus with a stable, crosslinking silyl group-containing    carbanion.

The above production method [K] is similar to the production method [E]for the (A1) component except that a vinyl polymer having a highlyreactive carbon-halogen bond at only one molecular chain terminus isused as the polymer. Such a vinyl polymer having a highly reactivecarbon-halogen bond at only one molecular chain terminus can be producedby the process [K-a] to be described later herein, among otherprocesses.

The processes [G-a]˜[G-j] for producing the vinyl polymer having analkenyl group at one molecular chain terminus, which is to be used inthe above production method [G], is described.

The following processes [G-a] and [G-b] are exemplary processes fordirectly synthesizing a vinyl polymer having an alkenyl group only atone molecular chain terminus by a living radical polymerizationtechnique using an initiator having one initiation point. The initiatorhaving one initiation point for use in this living radicalpolymerization will be described later herein.

-   [G-a] A process for synthesizing a vinyl polymer by a living radical    polymerization technique using an initiator having one initiation    point, which comprises reacting a compound having both a    polymerizable alkenyl group and a sparingly polymerizable alkenyl    group in a terminal stage of polymerization reaction or after    completion of the reaction of the predetermined vinyl monomer.

As the compound having both a polymerizable alkenyl group and asparingly polymerizable alkenyl group for use in the above productionprocess [G-a], there can be mentioned compounds represented by the abovegeneral formula (7).

-   [G-b] A process in which, in synthesizing a vinyl polymer by a    living radical polymerization technique using an initiator having    one initiation point, a compound having at least 2 sparingly    polymerizable alkenyl groups is reacted at a terminal stage of    polymerization reaction or after completion of the reaction of the    predetermined vinyl monomer.

The above compound having at least two sparingly polymerizable alkenylgroups is not particularly restricted but includes 1,5-hexadiene,1,7-octadiene and 1,9-decadiene, among others.

The following processes [G-c] to [G-f] are exemplary processes forconverting the halogen atom of a vinyl polymer having a highly reactivecarbon-halogen bond at only one molecular chain terminus to an alkenylgroup.

Regarding the method for substituting an alkenyl group for the halogenof a vinyl polymer having a highly reactive carbon-halogen bond at onlyone molecular chain terminus, processes corresponding to said processes[A-c] to [A-f] for producing the (A1) component can be employed. Thecorresponding processes [A-c] to [A-f] in which a vinyl polymer having ahighly reactive carbon-halogen bond at only one molecular chain terminusare now designated as processes [G-c] to [G-f] respectively. By theseprocesses [G-c] to [G-f], a vinyl polymer having an alkenyl group atonly one molecular chain terminus can be obtained. The polymer havingnot less than 1.1 of highly reactive carbon-halogen bond at only onemolecular chain terminus on the average per molecule can be obtained bythe process [K-a] to be described later herein, among others, howeverthis is not limited thereto.

The following processes [G-g] to [G-j] are exemplary processes forconverting the hydroxyl group of a vinyl polymer having a hydroxyl groupat only one molecular chain terminus to an alkenyl group.

The processes for converting the hydroxyl group of a vinyl polymerhaving a hydroxyl group at only one molecular chain terminus to analkenyl group may be comparable to said processes [A-g] to [A-j] forproducing the [A1] component. With the processes [A-g] to [A-j] in whicha vinyl polymer having a hydroxyl group at only one molecular chainterminus is used being designated as processes [G-g] to [G-j], a vinylpolymer having an alkenyl group at only one molecular chain terminus canbe obtained by any of the processes [G-g] to [G-j]. The above-mentionedpolymer having a hydroxyl group at only one molecular chain terminus canbe produced by any of the processes [H-a] to [H-f], among others.

Referring to the synthesis method of said vinyl polymer having analkenyl group at only one molecular chain terminus, when a halogen isnot directly involved in the introduction of an alkenyl group as in theprocesses [G-a] and [G-b], it is preferable to use the living radicalpolymerization technique. Between the above processes, the process [G-b]is preferred in view of the comparative ease of control. Amongvariations of living radical polymerization, atom transfer radicalpolymerization is preferred.

When an alkenyl group is to be introduced by converting the halogengroup of a vinyl polymer having a highly reactive carbon-halogen bond asin the processes [G-c] to [G-f], it is preferable to use a vinyl polymerhaving a highly reactive carbon-halogen bond at only one molecular chainterminus as obtained by a radical polymerization (atom transfer radicalpolymerization) reaction using an organohalogen compound having a highlyreactive carbon-halogen bond to be described hereinafter or a sulfonylhalide as the initiator and a transition metal complex as the catalyst.The more preferred is the process [G-f] in view of the ease of control.

The processes [H-a] to [H-f] for producing the vinyl polymer having ahydroxyl group at one molecular chain terminus, which is to be used inthe above production method [H] and processes [G-g] to [G-j], isdescribed below.

The following processes [H-a] and [H-b] are exemplary processes fordirectly synthesizing a vinyl polymer having a hydroxyl group at onemolecular chain terminus by a living radical polymerization techniqueusing an initiator having one initiation point. The initiator having oneinitiation point for use in this living radical polymerization techniquewill be described later herein.

-   [H-a] A process for synthesizing a vinyl polymer by a living radical    polymerization technique using an initiator having one initiation    point, which comprises reacting a compound having both a    polymerizable alkenyl group and a hydroxyl group in a terminal stage    of polymerization reaction or after completion of the reaction of    the predetermined vinyl monomer.

As the compound having both a polymerizable alkenyl group and a hydroxylgroup for use in the above production process [H-a], there can bementioned compounds represented by the above general formula (13).

-   [H-b] A process in which, in synthesizing a vinyl polymer by a    living radical polymerization technique using an initiator having    one initiation point, an alkenyl alcohol such as 10-undecenol,    5-hexenol or allyl alcohol is reacted at a terminal stage of    polymerization reaction or after completion of the reaction of the    predetermined monomer.

The following process [H-c] is an exemplary radical polymerizationprocess using a hydroxyl group-containing chain transfer agent orinitiator.

-   [H-c] This process comprises radical-polymerizing said vinyl monomer    using a hydroxyl-containing chain transfer agent, such as    mercaptoethanol, or a hydroxyl-containing azo initiator.

The following processes [H-d] to [H-f] are exemplary processes forconverting the halogen of a vinyl polymer having a highly reactivecarbon-halogen bond at only one molecular chain terminus to a hydroxylgroup.

The vinyl polymer having a highly reactive carbon-halogen bond at onlyone molecular chain terminus can be produced by the process [K-a] to bedescribed hereinafter, among others.

-   [H-d] A process which comprises reacting a vinyl polymer having a    highly reactive carbon-halogen bond at only one molecular chain    terminus with a hydroxyl group-containing stabilized carbanion such    as the one represented by the above general formula (14) to thereby    substitute a hydroxyl-containing substituent for said halogen.-   [H-e] The process which comprises permitting an elemental metal,    such as zinc, or an organometal compound to act on a vinyl polymer    having a highly reactive carbon-halogen bond at one molecular chain    terminus to prepare an enolate anion and reacting it with an    aldehyde or a ketone.-   [H-f] A process which comprises reacting a vinyl polymer having a    highly reactive carbon-halogen bond at only one molecular chain    terminus with a hydroxyl-containing oxyanion, such as the one    represented by the above general formula (15), or a    hydroxyl-containing carboxylate anion, such as the one represented    by the above general formula (16), to substitute a    hydroxyl-containing group for the halogen.

Referring to the above technology of converting the halogen of a vinylpolymer having a highly reactive carbon-halogen bond at only onemolecular chain terminus to a hydroxyl group, when the halogen is notdirectly involved in the introduction of a hydroxyl group as in theprocesses [H-a] to [H-c], it is preferable to use the living radicalpolymerization technique. The process [H-b] is preferred in view of theease of control. Among variations of living radical polymerization, atomtransfer radical polymerization is preferred.

When the synthesis method comprises introducing a hydroxyl group byconverting the highly reactive carbon-halogen bond as in the processes[H-d] to [H-f], it is preferable to use a vinyl polymer having a highlyreactive carbon-halogen bond at only one molecular chain terminus asobtained by a radical polymerization (atom transfer radicalpolymerization) reaction using an organohalogen or sulfonyl halidecompound to be described hereinafter as the initiator and a transitionmetal complex as the catalyst. The more preferred is the process [H-f]in view of the ease of control.

The process [K-a] for producing a vinyl polymer having a highly reactivecarbon-halogen bond at only one molecular chain terminus for use in theabove production method [K] and processes [G-c] to [G-f] and [H-d] to[H-f] is now described in detail.

-   [K-a] This process comprises polymerizing a vinyl monomer by an atom    transfer radical polymerization reaction using an initiator having    one highly reactive carbon-halogen bond.

The initiator which can be used in the above process [K-a] includesorganohalogen compounds having one highly reactive carbon-halogen bondand sulfonyl halide compounds, such as those represented by thefollowing formulas, among others.C₆H₅—CH₂X, C₆H₅—C(H)(X)CH₃, C₆H₅—C(X)(CH₃)₂(wherein C₆H₅ stands for a phenyl group; X represents a chlorine,bromine or iodine atom)R—C(H)(X)—CO₂R, R—C(CH₃)(X)—CO₂R, R—C(H)(X)—C(O)R, R—C(CH₃)(X)—C(O)R(wherein R represents a hydrogen atom or an alkyl, aryl or aralkyl groupcontaining up to 20 carbon atoms and the plurality of R groups may bethe same or different; X represents a chlorine, bromine or iodine atom)R—C₆H₄—SO₂X(wherein R represents a hydrogen atom or an alkyl, aryl or aralkyl groupcontaining up to 20 carbon atoms; X represents a chlorine, bromine oriodine atom)

These may be used each independently or two or more of them may be usedin a combination of two or more thereof.

The initiator having one initiation point for use in the above livingpolymerization varies with different modes of polymerization. Thus, inthe case of atom transfer radical polymerization, an organohalogencompound having one highly reactive carbon-halogen bond or a sulfonylhalide compound, such as described for [K-a] above, is used as theinitiator. In the living radical polymerization technique using aradical-capping agent such as a nitroxide or the like or in the livingradical polymerization technique utilizing a cobalt-porphyrin complex orthe like, a peroxide, such as benzoyl peroxide, or an azo compound, suchas azobisisobutyronitrile or azobisisovaleronitrile, can be used as theinitiator.

The vinyl polymer having a crosslinking silyl group at only onemolecular chain terminus can also be a vinyl polymer having acrosslinking silyl group at one molecular chain terminus and a highlyreactive carbon-halogen bond at the other molecular chain terminus asproduced by the method using an organohalogen compound having acrosslinking silyl group which corresponds to the method (F) forproducing the (A1) component, either as it is or after conversion ofsaid halogen to a group other than a crosslinking silyl group.

Similarly, the vinyl polymer having a crosslinking silyl group at onlyone molecular chain terminus can also be obtained by preparing a vinylpolymer having an alkenyl group at one molecular chain terminus and ahighly reactive carbon-halogen bond at the other terminus by the methodusing an organohalogen compound having an alkenyl group and convertingthe alkenyl group to a crosslinking silyl group by the technologydescribed above.

As mentioned hereinbefore, the crosslinking silyl group of the vinylpolymer having a crosslinking silyl group at only one molecular chainterminus as produced via said method [I] or any of processes [G-a],[G-b], [H-a], [H-b], etc. does not necessarily exist at the terminus ina strict sense of the term but may possibly be located only close to theterminus. However, the effect of addition of such a polymer isfundamentally not different from that of a polymer having said groupstrictly at the terminus. Therefore, such polymers are subsumed in theconcept of a vinyl polymer having a crosslinking silyl group of thegeneral formula (1) at only one molecular chain terminus for use as themain component of the reactive plasticizer (E) according to the fourthaspect of the invention.

The vinyl polymer having a crosslinking silyl group at only onemolecular chain terminus for the above reactive plasticizer (E) can beprepared by an optional combination of the processes describedhereinabove but as typical production technologies, methodscorresponding to the methods A and B described for (A1) component can bementioned.

The addition amount of the reactive plasticizer (E), based on 100 weightparts of the vinyl polymer (A4) having not less than 1.1 of crosslinkingsilyl groups of the general formula (1) on the average, is 5 to 150weight parts, preferably 10 to 120 weight parts, more preferably 20 to100 weight parts. At an addition amount below 5 weight parts, the effectexpected of a plasticizer is not expressed. If the amount of 150 weightparts is exceeded, the mechanical strength of the cured product will beinsufficient.

The curable composition according to the fourth aspect of the inventionmay be supplemented with various optional components similar to thosementioned for the first aspect of the invention.

The curable composition according to the fourth aspect of the inventioncan be prepared as a one-component system such that all the componentsare premixed and sealed and, after application, let the whole be curedin situ by atmospheric moisture or as a two-component system such that acuring agent comprising the curing catalyst, filler, plasticizer, water,etc. and a polymer composition are admixed prior to application.

The curable composition according to the fourth aspect of the inventioncan be used in a broad spectrum of applications, for example sealantssuch as architectural elastic sealants, composite-glass sealants,electric/electronic materials such as a solar cell back sealant, etc.,electrical insulating materials such as conductor/cable insulationsheaths, etc., adhesives, self-adhesives, elastic adhesives, coatings,powder coatings, coating dopes, foams, electric/electronic pottingmaterials, film, gaskets, potting compounds, various molding compounds,rust-preventive, and water-proofing sealants for wire-reinforced glassor laminated glass edges (cut edges).

<<The Fifth Aspect of the Invention>>

The curable composition according to the fifth aspect of the inventionis now described.

The curable composition according to the fifth aspect of the inventioncomprises (A5) a vinyl polymer having a crosslinking silyl group and (F)a silanol-containing compound.

[The Vinyl Polymer for (A5) Component]

The (A5) component according to the fifth aspect of the invention is avinyl polymer having a main chain produced by living radicalpolymerization and at least one crosslinking silyl group of the generalformula (1) on the average per molecule, which, as such, crosslinks andcures by siloxane bonding.

The general formula (1) representing the crosslinking silyl group (A5)is identical to the general formula (1) representing the crosslinkingsilyl group (A1) in the first aspect of the invention except that R¹ andR² may be the same or different and each represents an alkyl groupcontaining 1 to 20 carbon atoms, an aryl group containing 6 to 20 carbonatoms or an aralkyl group containing 7 to 20 carbon atoms.

The crosslinking silyl group of the general formula (1) should becontained in the number of at least one per polymer molecule. When thenumber of crosslinking silyl groups per molecule is less than 1 on theaverage, a sufficiently cured product cannot be obtained. The averagenumber of crosslinking silyl groups of the general formula (1) permolecule which is necessary to provide a sufficiently cured product isgenerally 1.1 to 5, preferably 1.2 to 4, more preferably 1.3 to 3.

The monomer constituting its main chain is not particularly restrictedas far as it is a vinyl monomer, and includes the monomeric compoundsmentioned for the first aspect of the invention.

From the standpoint of physical properties, the vinyl polymer having notless than 1.1 of the above crosslinking silyl groups on the average ispreferably a (meth)acrylic polymer synthesized by using a (meth)acrylicmonomer, among said various monomers, in a proportion of not less than40 weight %. The still more preferred is an acrylic polymer synthesizedby using an acrylic monomer, among said various monomers, in aproportion of not less than 30 weight %.

The number average molecular weight of the vinyl polymer having not lessthan 1.1 of said crosslinking silyl groups on the average is notparticularly restricted but is preferably within the range of 500 to100000. At a molecular weight less than 500, the intrinsiccharacteristics of a vinyl polymer are hardly manifested and, at above100000, handling may become difficult in some instances.

The molecular weight distribution, namely the ratio (Mw/Mn) of weightaverage molecular weight (Mw) to number average molecular weight (Mn),of the vinyl polymer having not less than 1.1 of said crosslinking silylgroups on the average per molecule is not particularly restricted. Forfacilitating handling by controlling the viscosity of the curablecomposition at a sufficiently low amount while securing necessary curedphysical properties, however, a narrow molecular weight distribution ispreferred. The molecular weight distribution value is preferably lessthan 1.8, more preferably not more than 1.7, still more preferably notmore than 1.6, yet more preferably not more than 1.5, still morepreferably not more than 1.4, most preferably not more than 1.3. Themolecular weight distribution is most prevalently determined by gelpermeation chromatography (GPC). The number average molecular weight andso on can be determined on the polystyrene equivalent basis usingchloroform or THF as the mobile phase and polystyrene gel columns ascolumns.

The vinyl polymer for use as the (A5) component in accordance with thefifth aspect of the invention is prepared by living polymerization.Unlike free radical polymerization or the like, this polymerizationtechnique provides for an accurate control over the introduction of acrosslinking silyl group. Thus, since, as a feature of livingpolymerization, a crosslinking silyl group can be introduced into theterminus or terminal region of the polymer with quite high probability,not only a reduction in modulus but also an increase in gel fraction canbe made feasible. Furthermore, because of the “living” mode of radicalpolymerization, the molecular weight distribution as a major determinantof viscosity of the polymer can be decreased to effect reductions inviscosity of the polymer and curable composition.

However, there is a limit to the reduction in modulus which can berealized only with the vinyl polymer having a crosslinking silyl group(A5) whose main chain has been synthesized by living polymerization. Thefifth aspect of the present invention is characterized in that the vinylpolymer (A5) whose main chain has been synthesized by livingpolymerization and has a crosslinking silyl group at at least oneterminus thereof is used in combination with a silanol group-containingcompound (F) to be described later herein, whereby the modulus-reducingeffect is augmented as compared with the case in which a vinyl polymersynthesized by the conventional free radical polymerization technologyis used.

While the living polymerization technology referred to above includesliving anionic polymerization, living cationic polymerization and livingradical polymerization techniques, among others, any of these techniquescan be liberally employed in the fifth aspect of the invention. Themethod of introducing said crosslinking silyl group into the vinylpolymer is not particularly restricted, either, but various techniquescan be employed.

However, from the standpoint of monomer universality and ease ofcontrol, the living radical polymerization technique for introducing acrosslinking silyl group directly into the main chain and the techniquewhich comprises synthesizing a vinyl polymer having a given functionalgroup capable of converting to a crosslinking silyl group in one or morereaction steps and converting the given functional group to thecrosslinking silyl group are preferred. In particular, an atom transferradical polymerization is more preferred.

The living radical polymerization technique is advantageous in thatdespite its also being a method for radical polymerization reactionwhich is generally considered to be hardly controllable because of thehigh polymerization velocity and high tendency of termination byradical-radical coupling or the like, a termination reaction does noteasily take place, thus giving a polymer with a narrow molecular weightdistribution (Mw/Mn=about 1.1 to 1.5), and further in that the molecularweight can be freely controlled by adjusting the monomer-initiatorcharge ratio.

Since it is thus capable of giving a polymer having a narrow molecularweight distribution and a low viscosity and enables introduction of amonomer having a given functional group in a more or less plannedposition, the living radical polymerization is a further preferredmethod for producing said vinyl polymer having the defined functionalgroup.

As the specific technology of producing the (A5) component, there can bementioned various processes corresponding to those described for thefirst aspect of the invention, with the exception of the processes usingany mode of polymerization other than living polymerization. Typicalprocesses are those corresponding to the above synthetic methods A and Bdescribed for the (A1) component.

When rubber-like properties are especially required of a cured productobtainable from the curable composition according to this fifth aspectof the invention, it is preferable that at least one crosslinking silylgroup is present at the molecular chain terminus, for the molecular massbetween crosslinking points, which has considerable bearings on rubberelasticity, can then be large. More preferred is a polymer having acrosslinking silyl group at both termini of the molecular chain. Stillmore preferably, all crosslinking silyl groups are present at molecularchain termini.

[The Silanol-Containing Compound for (F) Component]

The “silanol-containing compound” in the context of the fifth aspect ofthe invention is a compound (I) having one silanol group within themolecule and/or a compound (II) capable of reacting with moisture togive a compound having one silanol group within the molecule. Whicheveralone of these compounds can be used or both compounds may be used incombination.

The compound (I) having one silanol group within the molecule, i.e. oneof (F) component for use in this invention, is not particularlyrestricted but includes compounds represented in the following:

compounds which may be represented by the formula (R″)₃SiOH (wherein theR″ groups may be the same or different and each represents a substitutedor unsubstituted alkyl or aryl group), such as(CH₃)₃SiOH, (CH₃CH₂)₃SiOH, (CH₃CH₂CH₂)₃SiOH, (n-Bu)₃SiOH, (sec-Bu)₃SiOH,(t-Bu)₃SiOH, (t-Bu)Si(CH₃)₂OH, (C₅H₁₁)₃SiOH, (C₆H₁₃)₃SiOH, (C₆H₅)₃SiOH,(C₆H₅)₂Si(CH₃)OH, (C₆H₅)Si(CH₃)₂OH, (C₆H₅)₂Si(C₂H₅)OH, C₆H₅Si(C₂H₅)₂OH,C₆H₅CH₂Si(C₂H₅)₂OH, C₁₀H₇Si(CH₃)₂OH,(in the above formulas, C₆H₅ stands for a phenyl group; C₁₀H₇ stands fora naphthyl group);

silanol-containing cyclic polysiloxane compounds, such as

silanol-containing linear polysiloxane compounds, such as

compounds whose main chains are polymers containing silicon and carbonatoms and each having a silanol group at a molecular chain terminus;

compounds whose main chains are polysilanes each having a silanol groupat a molecular chain terminus,

and

compounds whose main chains are polymers containing silicon, carbon andoxygen atoms and each having a silanol group at a molecular chainterminus, such as

The preferred, among these, are compounds represented by the followinggeneral formula (48).(R²⁶)₃SiOH  (48)(wherein R²⁶ represents a hydrocarbon group containing 1 to 20 carbonatoms and the plurality of R²⁶ groups may be the same or different)

The R²⁶ group is preferably a methyl, ethyl, vinyl, t-butyl or phenylgroup, more preferably a methyl group.

Among these, a compound of low molecular weight, such as (CH₃)₃SiOH, ispreferred from the standpoint of availability and effect of addition.

The above compound having one silanol group, i.e. compound (I), appearsto react with the crosslinking silyl group of the vinyl polymer (A5) orthe siloxane bond formed on crosslinking thereof to reduce the number ofcrosslinks, thus imparting flexibility to the cured product.

The compound (II) capable of reacting with moisture to give a compoundhaving one silanol group therein, the one kind of (F) component, is notparticularly restricted but is preferably a compound capable of reactingwith moisture to give a silanol-containing compound of the above generalformula (48) (as the hydrolysate). Thus, such compound includes but isnot limited to the following compounds as well as the compounds of thegeneral formula (49) to be described later herein.

Thus, N,O-bis(trimethylsilyl)acetamide, N-(trimethylsilyl)acetamide,bis(trimethylsilyl)trifluoroacetamide,N-methyl-N-trimethylsilyltrifluoroacetamide, bistrimethylsilylurea,N-(t-butyldimethylsilyl)N-methyltrifluoroacetamide,(N,N-dimethylamino)trimethylsilane, (N,N-diethylamino)trimethylsilane,hexamethyldisilazane, 1,1,3,3-tetramethyldisilazane,N-(trimethylsilyl)imidazole, trimethylsilyltrifluoromethane sulfonate,trimethylsilyl phenoxide, trimethylsilyl-n-octanol,trimethylsilyl-2-ethylhexanol, tris(trimethylsilyl)glycerol,tris(trimethylsilyl)trimethylolpropane,tris(trimethylsilyl)pentaerythritol,tetra(trimethylsilyl)pentaerythritol, (CH₃)₃SiNHSi(CH₃)₃,(CH₃)₃SiNSi(CH₃)₂, and

can be used with advantage. From the standpoint of the silanol contentof the hydrolysate, (CH₃)₃SiNHSi(CH₃)₃ is particularly preferred.

The preferred compound (II) capable of reacting with moisture to give acompound having one silanol group per molecule, said one kind of (F)component, includes not only the above-mentioned compounds but alsocompounds represented by the following general formula (49).((R²⁶)₃SiO)_(n)R²⁷  (49)(wherein R²⁶ has the same meaning as defined above; n represents apositive number; R²⁷ represents a group derived from an activehydrogen-containing compound by removal of part or the whole of activehydrogen)

R²⁸ is preferably a methyl, ethyl, vinyl, t-butyl or phenyl group, morepreferably a methyl group.

The (R²⁶)₃Si group is preferably a trimethylsilyl group; all the threeR²⁶ groups are methyl groups. Moreover, n is preferably equal to 1 to 5.

The active hydrogen-containing compound from which R²⁷ is derived is notparticularly restricted but includes alcohols such as methanol, ethanol,n-butanol, i-butanol, t-butanol, n-octanol, 2-ethylhexanol, benzylalcohol, ethylene glycol, diethylene glycol, polyethylene glycol,propylene glycol, dipropylene glycol, polypropylene glycol, propanediol,tetramethylene glycol, poly(tetramethylene glycol), glycerol,trimethylolpropane, pentaerythritol, etc.; phenols such as phenol,cresol, bisphenol A, hydroquinone, etc.; carboxylic acids such as formicacid, acetic acid, propionic acid, lauric acid, palmitic acid, stearicacid, behenic acid, acrylic acid, methacrylic acid, oleic acid, linoleicacid, linolenic acid, sorbic acid, oxalic acid, malonic acid, succinicacid, adipic acid, maleic acid, benzoic acid, phthalic acid,terephthalic acid, trimellitic acid, etc.; ammonia; amines such asmethylamine, dimethylamine, ethylamine, diethylamine, n-butylamine,imidazole, etc.; acid amides such as acetamide, benzamide, etc.; ureacompounds such as urea, N,N′-diphenylurea, etc.; and ketones such asacetone, acetylacetone, 2,4-heptadione, etc.; among others.

The compound (II) capable of reacting with moisture to give a compoundhaving one silanol group within the molecule, as represented by thegeneral formula (49), can be obtained, for example by reacting saidactive hydrogen-containing compound with a compound having both an(R²⁶)₃Si group (R²⁶ has the same meaning as above) and a halogen orother group capable of reacting with active hydrogen, which is known asa silylating agent, such as trimethylsilyl chloride ordimethyl(t-butyl)chloride.

The compound represented by the general formula (49) includes but is notlimited to allyloxytrimethylsilane, N,O-bis(trimethylsilyl)acetamide,N-(trimethylsilyl)acetamide, bis(trimethylsilyl)trifluoroacetamide,N-methyl-N-trimethylsilyltrifluoroacetamide, bistrimethylsilylurea,N-(t-butyldimethylsilyl)N-methyltrifluoroacetamide,(N,N-dimethylamino)trimethylsilane, (N,N-diethylamino)trimethylsilane,hexamethyldisilazane, 1,1,3,3-tetramethyldisilazane,N-(trimethylsilyl)imidazole, trimethylsilyltrifluoromethane sulfonate,trimethylsilyl phenoxide, trimethylsilyl-n-octanol,trimethylsilyl-2-ethylhexanol, tris(trimethylsilyl)glycerol,tris(trimethylsilyl)trimethylolpropane,tris(trimethylsilyl)pentarythritol andtetra(trimethylsilyl)pentaerythritol. These may be used eachindependently or in a combination of two or more thereof.

Furthermore, compounds which may be represented by the general formula((CR²⁸)₃SiO)(R²⁹O)_(s))_(t)Z (wherein R²⁸ may be the same or differentand each represents a univalent hydrocarbon group, substituted orunsubstituted, or a hydrogen atom; R²⁹ represents a bivalent hydrocarbongroup containing 1˜8 carbon atoms, s and t each represents a positivenumber such that s is equal to 1˜6 and s×t is not less than 5; Zrepresents a univalent through hexavalent organic group), for exampleCH₃O(CH₂CH(CH₃)O)₅Si(CH₃) 3, CH₂═CHCH₂ (CH₂CH(CH₃)O)₅Si(CH₃)₃,(CH₃)₃SiO(CH₂CH(CH₃)O)₅Si(CH₃)₃, (CH₃)₃SiO(CH₂CH(CH₃)O)₇Si(CH₃)₃, etc.,can also be used with advantage. These may be used each independently orin a combination of two or more thereof.

Referring to said compound (II) capable of reacting with moisture togive a compound having one silanol group within the molecule, thepreferred active hydrogen compounds are phenols, acid amides andalcohols and the more preferred are phenols and alcohols, which havehydroxyl groups, for these compounds do not adversely affect the storagestability, weather resistance and other properties.

The preferred, among the compounds mentioned above, areN,O-bis(trimethylsilyl)acetamide, N-(trimethylsilyl)acetamide,trimethylsilyl phenoxide, trimethylsilyl-n-octanol,trimethylsilyl-2-ethylhexanol, tris(trimethylsilyl)glycerol,tris(trimethylsilyl)trimethylolpropane,tris(trimethylsilyl)pentaerythritol andtetra(trimethylsilyl)pentaerythritol.

The compounds (II) capable of reacting with moisture to give a compoundhaving one silanol group within the molecule reacts with moisture duringstorage, in curing or after curing to give a compound having one silanolgroup per molecule. It appears that the compound having one silanolgroup thus produced reacts with the crosslinking silyl group of thevinyl polymer (A5) or the siloxane bond formed on crosslinking thereofto reduce the number of crosslinks, thus contributing to the flexibilityof the cured product.

The addition amount of the silanol-containing compound as the (F)component can be adjusted according to the expected physical propertiesof the cured product.

The addition amount of the silanol-containing compound (F) may be 0.1 to50 weight parts, preferably 0.3 to 20 weight parts, more preferably 0.5to 10 weight parts, based on 100 weight parts of the vinyl polymer (A5).At an amount below 0.1 weight part, the effect of addition of (F) is notexpressed. Over 50 weight parts, crosslinking is insufficient and thestrength and gel fraction of the cured product are considerablydecreased.

The timing of addition of said silanol-containing compound (F) to thevinyl polymer (A5) is not particularly restricted. Thus, the (F)component may be added in the stage of production of the vinyl polymer(A5) or at the preparation of the curable composition.

The curable composition according to the fifth aspect of the inventionmay be supplemented with various optional components similar to thosementioned for the first aspect of the invention.

The curable composition according to the fifth aspect of the presentinvention can be provided as a one-component system such that all thecomponents are premixed and sealed and, after application, let the wholebe cured in situ by atmospheric moisture or as a two-component systemsuch that a curing agent comprising the curing catalyst, filler,plasticizer, water, etc. and a polymer composition are admixed prior toapplication.

The curable composition according to the fifth aspect of this inventioncan be used in a broad spectrum of applications, for example sealantssuch as architectural elastic sealants, composite-glass sealants,electric/electronic materials such as a solar cell back sealant, etc.,electrical insulating materials such as conductor/cable insulationsheaths, adhesives, self-adhesives, elastic adhesives, coatings, powdercoatings, coating dopes, foams, electric/electronic potting materials,film, gaskets, potting compounds, various molding compounds,rust-preventive, water-proofing sealants for wire-reinforced glass orlaminated glass edges (cut edges) and so on.

BEST MODE FOR CARRYING OUT THE INVENTION

The following examples and comparative examples illustrate the presentinvention in further detail, it being, however, to be understood thatthese examples are by no means definitive of the scope of the invention.

In the following examples and comparative examples, all “parts” and “%”are “parts by weight” and “weight %”, respectively.

As referred to in the following examples, the “number average molecularweight” and “molecular weight distribution (ratio of weight averagemolecular weight to number average molecular weight)” are the valuesdetermined by gel permeation chromatography (GPC) based on polystyrenestandards. Thus, columns packed with crosslinked polystyrene gels wereused as the GPC columns and chloroform-was used as the GPC solvent.

EXAMPLES RELATING TO THE FIRST ASPECT OF THE INVENTION ProductionExample 1

A 10-L separable flask equipped with a reflux-condenser and a stirrerwas charged with CuBr (28.0 g, 0.195 mol). After nitrogen gas purging,acetonitrile (559 mL) was added and the mixture was stirred on an oilbath at 70 C for 15 minutes. Thereafter, butyl acrylate (1.00 kg),diethyl 2,5-dibromoadipate (117 g, 0.325 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (1.70 mL, 1.41 g, 8.14 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(4.00 kg) was continuously added dropwise over 175 minutes. In thecourse of dripping butyl acrylate, triamine (8.50 mL, 7.06 g, 40.7 mol)was further added. At 370 minutes after initiation of the reaction,1,7-octadiene (1.57 L, 1.17 kg, 7.10 mol) and triamine (20.4 mL, 16.9 g,97.7 mmol) were added, and the whole mixture was stirred under heatingat 70 C for 220 minutes.

This reaction mixture was diluted with hexane and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [1]) was obtained. This polymer [1] had a number averagemolecular weight of 21300 and a molecular weight distribution value of1.3.

A 2-L separable flask equipped with a condenser was charged with polymer[1] (0.73 kg), potassium benzoate (25 g) and N,N-dimethylacetamide (0.7L) and the mixture was stirred under nitrogen at 70° C. for 12 hours.The N,N-dimethylacetamide was distilled off under reduced pressure andthe residue was diluted with toluene and treated with an activatedalumina column to remove the toluene-insoluble matter (KBr and excesspotassium benzoate). The volatile fraction of the filtrate was thendistilled off under reduced pressure to give polymer [2].

A 2-L round-bottom flask equipped with a condenser was charged withpolymer [2] (0.73 kg), aluminum silicate (150 g, product of KyowaChemical, Kyowaad 700 PEL) and toluene (4.0 L) and the mixture wasstirred under nitrogen at 100° C. for 5 hours. The aluminum silicate wasthen filtered off and the toluene in the filtrate was distilled offunder reduced pressure to give polymer [3].

A 1-L pressure-resisting reaction vessel was charged with polymer [3](390 g), dimethoxymethylhydrosilane (36.0 mL, 0.292 mol), methylorthoformate (7.10 mL, 0.065 mol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. However,the amount of use of the platinum catalyst was 10⁻² molar equivalentswith respect to the alkenyl group of the polymer. This reaction mixturewas heated at 100° C. for 400 minutes. The volatile fraction of themixture was then distilled off under reduced pressure to give asilyl-terminated polymer (polymer [4]). This polymer had a numberaverage molecular weight (GPC method, polystyrene equivalent) of 246000and a molecular weight distribution value of 1.5. The average number ofsilyl groups introduced per mole of the polymer was 3.0 as determined by¹H NMR analysis.

Production Example 2

A 2-L separable flask equipped with a reflux-condenser and a stirrer wascharged with CuBr (22.4 g, 0.156 mol), followed by nitrogen gas purging.Then, acetonitrile (112 mL) was added and the mixture was stirred on anoil bath at 70 C for 30 minutes. Thereafter, butyl acrylate (0.20 kg),methyl 2-bromopropionate (86.9 g, 0.520 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (0.19 mL, 0.18 g, 1.04 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(0.80 kg) was continuously added dropwise over 150 minutes. In thecourse of dripping butyl acrylate, triamine (1.81 mL, 1.71 g, 9.88 mol)was further added. The whole mixture was stirred under heating at 70° C.for 230 minutes.

This reaction mixture was diluted with toluene and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [5]) was obtained. This polymer [5] had a number averagemolecular weight of 2600 and a molecular weight distribution value of1.18.

A 2-L separable flask equipped with a condenser was charged with polymer[5] (0.937 kg), potassium acetate (73.5 g) and N,N-dimethylacetamide(0.8 L) and the mixture was stirred under nitrogen at 70° C. for 5hours. The N,N-dimethylacetamide was distilled off under reducedpressure and the residue was diluted with toluene and treated with anactivated alumina column to remove the toluene-insoluble matter (KBr andexcess potassium benzoate). The volatile fraction of the filtrate wasthen distilled off under reduced pressure to give polymer [6]

Example 1

One-hundred parts of the polymer [4] obtained in Production Example 1, 3parts of pentaerythritol triacrylate [(CH₂═CHCOOCH₂)₃CCH₂OH], 50 partsof polymer [6] as plasticizer, and 100 parts of Calfine 100 (Product ofMaruo Calcium) as filler were admixed under stirring. Then, 2 parts ofγ-glycidoxypropyltrimethoxysilane and 1 part of Sn(IV) catalyst(dibutyltin diacetylacetonate) were added and stirred and the wholemixture was degassed and molded to give a cured product in the form of a2 mm (approx.)-thick flat sheet and a cured product in a plano-convexform with a maximum thickness of about 5 mm on a glass sheet. Curing waseffected by allowing each product in a sunlit interior environment (neara window) for 2 days and further at 50° C. for 3 days. After curing, thesheet was tested for residual tack (surface tackiness) by the fingertouch method and, then, let standing outdoors. The plano-convex curedproduct was irradiated through the glass, immediately after curing, witha xenon weather-o-meter (product of Suga Testing Instruments, ModelSX120, illuminance 180 W, black panel temperature 63° C., rainfall time18 min. during a total irradiation time of 2 hrs) for 500 hours. Thesample was then subjected to a manual peel test. The results are shownin Table 1.

Example 2

Except that trimethylolpropane triacrylate [(CH₂═CHCOOCH₂)₃CCH₂CH₃] wasused in lieu of the pentaerythritol triacrylate used in Example 1, theprocedure of Example 1 was otherwise repeated faithfully to fabricatecured products. The evaluations were also performed as in Example 1. Theresults are shown in Table 1.

Comparative Example 1

Except that the pentaerythritol triacrylate used in Example 1 wasomitted, cured products were fabricated and evaluated in otherwise thesame manner as in Example 1. The results are shown in Table 1.

TABLE 1 Cured surface condition when photocurable substance (B) is usedCompar. Example 1 Example 2 Ex. 1 Photocurable PentaerythritolTrimethylol- — substance triacrylate propane triacrylate Residual tack ◯◯ Δ Manual peel test (Initial) ◯ ◯ ◯ (After 500 hrs) ◯ ◯ Δ In Table 1,Residual tack: Not tacky ← ⊚ > ◯ > Δ > X → Tacky Manual peel test:Cohesive failure (CF) ← ◯ > Δ > X → Adhesion failure (AF)

EXAMPLES RELATING TO THE SECOND ASPECT OF THE INVENTION ProductionExample 3

A 10-L separable flask equipped with a reflux-condenser and a stirrerwas charged with CuBr (42.0 g, 0.293 mol), followed by nitrogen gaspurging. Then, acetonitrile (559 mL) was added and the mixture wasstirred on an oil bath at 70 C for 45 minutes. Thereafter, butylacrylate (1.00 kg), diethyl 2,5-dibromoadipate (176 g, 0.488 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (2.00 mL, 1.66 g, 9.58 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(4.00 kg) was continuously added dropwise over 190 minutes. In thecourse of dripping butyl acrylate, triamine (6.00 mL, 4.98 g, 28.8 mol)was further added. At 310 minutes after initiation of the reaction,1,7-octadiene (1.44 L, 1.07 kg, 9.75 mol) and triamine (20.5 mL, 17.0 g,98.1 mmol) were added, and the whole mixture was stirred under heatingat 70° C. for 210 minutes.

This reaction mixture was diluted with hexane and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [7]) was obtained. This polymer [7] had a number averagemolecular weight of 14000 and a molecular weight distribution value of1.3.

A 10-L separable flask equipped with a condenser was charged withpolymer [7] (2.7 kg), potassium benzoate (142 g) andN,N-dimethylacetamide (2.7 L) and the mixture was stirred under nitrogenat 70° C. for 25 hours. The N,N-dimethylacetamide was distilled offunder reduced pressure and the residue was diluted with toluene andtreated with an activated alumina column to remove the toluene-insolublematter (KBr and excess potassium benzoate). The volatile fraction of thefiltrate was then distilled off under reduced pressure to give polymer[8].

A 2-L round-bottom flask equipped with a condenser was charged withpolymer [8] (2.7 kg), aluminum silicate (540 g, product of KyowaChemical, Kyowaad 700 PEL) and toluene (2.7 L) and the mixture wasstirred under nitrogen at 100° C. for 5 hours. The aluminum silicate wasthen filtered off and the toluene in the filtrate was distilled offunder reduced pressure to give polymer [9].

A 1-L pressure-resisting reaction vessel was charged with polymer [9](409 g), dimethoxymethylhydrosilane (27.0 mL, 0.22 mol), methylorthoformate (8.0 mL, 0.07 mmol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was 10⁻³ molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 1 hour. The volatile fraction of the mixture wasthen distilled off under reduced pressure to give a silyl-terminatedpolymer (polymer [10]). This polymer had a number average molecularweight (GPC method, polystyrene equivalent) of 13900 and a molecularweight distribution value of 1.4. The average number of silyl groupsintroduced per mole of the polymer was 1.5 as determined by ¹H NMRanalysis.

Example 3

One-hundred parts of the polymer [10] obtained in Production Example 3and 3 parts of tung oil were admixed, followed by addition of 1 part ofSn(IV) catalyst (dibutyitin diacetylacetonate) with stirring, and thewhole mixture was degassed under reduced pressure and molded to give acured product in the form of a 2 mm-thick flat sheet. On the followingday, the sheet was tested for residual tack by the finger touch method.Furthermore, the cured product was left standing outdoors for one monthand the degree of surface fouling was examined. The results are shown inTable 2.

Example 4

Except that tung oil was used in a proportion of 5 parts in lieu of 3parts, a cured product was fabricated and evaluated in the same manneras in Example 3. The results are shown in Table 2.

Comparative Example 2

Except that the tung oil used in Example 3 was omitted from theformulation, a cured product was fabricated and evaluated in otherwisethe same manner as in Example 3. The results are shown in Table 2.

TABLE 2 Cured surface condition when air oxidation-curable substance (C)is used Comparative Example 3 Example 4 Example 2 Tung oil 3 5 0 (part)Residual tack ⊚ ⊚ Δ Fouling, after ⊚ ⊚ ◯ one month In Table 2, Residualtack: Not tacky ← ⊚ > ◯ > Δ > X → Tacky Fouling: Clean ← ⊚ > ◯ > Δ > X →Smudgy (much adherent matter)

Example 5

A cured product was fabricated in the same manner as in Example 3,except that curing was effected by allowing the sample to stand in aninterior environment for 2 days and further at 50° C. for 3 days. Fromthe cured product in the form of a sheet, a No. 2 (⅓) dumbbell testpiecewas punched out and subjected to tensile testing with ShimadzuCorporation's autograph (measuring conditions: 23° C., 200 mm/min). Theresults are shown in Table 3.

Example 6

A cured product similar to the one according to Example 4 was fabricatedusing the same curing conditions as in Example 5 and evaluated in thesame manner as in Example 5. The results are shown in Table 3.

Comparative Example 3

A cured product similar to the one according to Comparative Example 2was fabricated using the same curing conditions as in Example 5 andevaluated in the same manner as in Example 5. The results are shown inTable 3.

TABLE 3 Tensile characteristics when air oxidation- curable substance(C) is used M50 M100 Tmax (MPa) (MPa) (MPa) Eb (%) Example 5 0.081 0.150.21 140 Example 6 0.082 0.15 0.15 110 Compar. Ex. 3 0.081 0.15 0.17 120

Example 7

Specimens of the cured sheet prepared in Example 3 were coated withvarious alkyd coatings and left standing indoors. After a predeterminedperiod of time, the coated surface was touched with a finger to assessthe degree of curing. The results are shown in Table 4.

Example 8

The cured sheet obtained in Example 4 was evaluated as in Example 7. Theresults are shown in Table 4.

Comparative Example 4

The cured sheet obtained in Comparative Example 2 was evaluated as inExample 7. The results are shown in Table 4.

TABLE 4 Alkyd coating coatability when air oxidation-curable substance(C) is used. Comparative Coating Example 7 Example 8 Example 4Schakelverf ◯/◯ ◯/◯ ◯/◯ Rubbol AZ ◯Δ/◯ ◯Δ/◯ Δ/◯Δ Sigmasolid ◯Δ/◯ ◯Δ/◯Δ/◯Δ semigloss Table 4 shows the evaluation after 1 day/the evaluationafter 7 days. ◯: completely cured Δ: Tacky X: Uncured The alkyd coatingsused are: Schakelverf: Product of Sigma Rubbol AZ: Product of AkzoSigmasolid semigloss: Product of Sigma

EXAMPLES RELATING TO THE THIRD ASPECT OF THE INVENTION ProductionExample 4

A 10-L separable flask equipped with a reflux-condenser and a stirrerwas charged with CuBr (42.0 g, 0.293 mol), followed by nitrogen gaspurging. Then, acetonitrile (559 mL) was added and the mixture wasstirred on an oil bath at 70° C. for 45 minutes. Thereafter, butylacrylate (1.00 kg), diethyl 2,5-dibromoadipate (176 g, 0.488 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (4.00 mL, 3.32 g, 19.2 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(4.00 kg) was continuously added dropwise over 190 minutes. In thecourse of dripping butyl acrylate, triamine (4.00 mL, 3.32 g, 0.0192mol) was further added. At 310 minutes after initiation of the reaction,1,7-octadiene (1.44 L, 1.07 kg, 9.75 mol) and triamine (20.5 mL, 17.0 g,98.1 mol) were added, and the whole mixture was stirred under heating at70 C for 210 minutes.

This reaction mixture was diluted with hexane and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [11]) was obtained. This polymer [11] had a number averagemolecular weight of 14000 and a molecular weight distribution value of1.3.

A 10-L separable flask equipped with a condenser was charged withpolymer [11] (2.7 kg), potassium benzoate (142 g) andN,N-dimethylacetamide (2.7 L) and the mixture was stirred under nitrogenat 70° C. for 25 hours. The N,N-dimethylacetamide was distilled offunder reduced pressure and the residue was diluted with toluene andtreated with an activated alumina column to remove the toluene-insolublematter (KBr and excess potassium benzoate). The volatile fraction of thefiltrate was then distilled off under reduced pressure to give polymer[12].

A 2-L round-bottom flask equipped with a condenser was charged withpolymer [12] (2.7 kg), aluminum silicate (540 g, product of KyowaChemical, Kyowaad 700 PEL) and toluene (2.7 L) and the mixture wasstirred under nitrogen at 100° C. for 5 hours. The aluminum silicate wasthen filtered off and the toluene in the filtrate was distilled offunder reduced pressure to give polymer [13].

A 1-L pressure-resisting reaction vessel was charged with polymer [13](760 g), dimethoxymethylhydrosilane (46.3 mL, 0.38 mol), methylorthoformate (13.7 mL, 0.13 mmol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was 10⁻³ molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 1 hour. The volatile fraction of the mixture wasthen distilled off under reduced pressure to give a silyl-terminatedpolymer (polymer [14]). This polymer had a number average molecularweight (GPC method, polystyrene equivalent) of 15000 and a molecularweight distribution value of 1.4. The average number of silyl groupsintroduced per mole of the polymer was 2.0 as determined by ¹H NMRanalysis.

Production Example 5

A 2-L separable flask equipped with a reflux-condenser and a stirrer wascharged with CuBr (22.4 g, 0.156 mol), followed by nitrogen gas purging.Then, acetonitrile (112 mL) was added and the mixture was stirred on anoil bath at 70° C. for 30 minutes. Thereafter, butyl acrylate (0.20 kg),methyl 2-bromopropionate (86.9 g, 0.520 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (0.19 mL, 0.18 g, 1.04 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(0.80 kg) was continuously added dropwise over 150 minutes. In thecourse of dripping butyl acrylate, triamine (1.81 mL, 1.71 g, 9.88 mmol)was further added. The whole mixture was stirred under heating at 70° C.for 230 minutes.

This reaction mixture was diluted with toluene and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby-an alkenyl group-terminated polymer(polymer [15]) was obtained. This polymer [15] had a number averagemolecular weight of 2600 and a molecular weight distribution value of1.18.

A 2-L separable flask equipped with a condenser was charged with polymer[15] (0.937 kg), potassium acetate (73.5 g) and N,N-dimethylacetamide(0.8 L) and the mixture was stirred under nitrogen at 70° C. for 5hours. The N,N-dimethylacetamide was distilled off under reducedpressure and the residue was diluted with toluene and treated with anactivated alumina column to remove the toluene-insoluble matter (KBr andexcess potassium benzoate). The volatile fraction of the filtrate wasthen distilled off under reduced pressure to give polymer [16].

Example 9

One-hundred parts of the polymer [14] obtained in Production Example 4and 50 parts of one of various high molecular plasticizers were admixed,followed by addition of 1 part of Sn(IV) catalyst (dibutyltindiacetylacetonate) with stirring, and the whole mixture was degassedunder reduced pressure and molded to give a cured product in the form ofa 2 mm-thick flat sheet. Curing was effected by allowing the sample tostand in an interior environment for 2 days and further at 50° C. for 3days. From the cured product in the form of a sheet, a No. 2 (⅓)dumbbell testpiece was punched out and subjected to tensile testing withShimadzu Corporation's autograph (measuring conditions: 23 C, 200mm/min). Viscosity measurements were carried out using a Type Eviscosimeter (EHD3° cone 28 φ used) at 23° C. The results are shown inTable 5.

Comparative Example 5

Using various low molecular plasticizers in lieu of the high molecularplasticizers used in Example 9, cured products were fabricated andsubjected to tensile testing in otherwise the same manner as in Example9. Viscosity measurements were also carried out in the same manner as inExample 9. The results are shown in Table 5.

In Table 5, the polyadipate polymer plasticizer is the product of AsahiElectric Works, Ltd., the polybutene plasticizer is the product ofIdemitsu Petrochemical Co., Ltd. and the alkylbenzene plasticizer is theproduct of Nippon Petrochemicals Co., Ltd.

TABLE 5 The viscosity and initial tensile properties of the compositionwhen the high molecular plasticizer (D) is used Molecular weight ofViscosity Eb Plasticizer plasti (Pa · s) M50 Tmax (%) Ex. 9 AcrylicPolymer 2600 37 0.05 0.14 180 [16] Polyadipate PN-280 3100 31 0.07 0.15100 PN-606 2700 28 0.08 0.20 130 PN-260 2800 25 0.07 0.14 100 PN-1701800 16 0.06 0.14 120 Compar. Ex. 5 Phthalate DOP 390 6 0.05 0.07 70DOTP 394 6 0.05 0.07 70 Adipate DOA 370 3 0.05 0.07 70 DINA 398 18 0.050.07 70 Trimellitate TOTM 546 10 0.06 0.11 100 Sebacate DOS 426 3 0.060.07 70 Polybutene Polybutene 720 44 0.07 0.14 100 35H AlkylbenzeneAlkene 330 9 0.04 0.07 90 100P Alkene 325 7 0.05 0.15 140 200P PhosphateTricresyl 368 8 0.07 0.08 60 phosphate Reference (blank) — 58 0.16 0.2690

Example 10

Some specimens of the cured sheet prepared in Example 9 (dumbbellspecimens) were set and kept stationary in a dryer at 150° C. After apredetermined time, the specimens were taken out and subjected totensile testing in the same manner as in 10. Example 9. The results areshown in Table 6.

Comparative Example 6

Some specimens of the cured sheet prepared in Comparative Example 5(dumbbell specimens) were set and kept stationary in a dryer at 150° C.as in Example 10. After a predetermined time, the specimens were takenout and subjected to tensile testing in the same manner as in Example10. The results are shown in Table 6.

TABLE 6 Effect of high molecular plasticizer (D) on heat resistance(tensile properties) Plasticizer Initial After 1 W After 4 W Ex. 10Polymer M50 (MPa) 0.05 0.06 0.04 [16] Tb (MPa) 0.14 0.24 0.20 Eb (%) 180230 230 PN-280 M50 (MPa) 0.07 0.10 0.19 Tb (MPa) 0.15 0.20 0.34 Eb (%)100 100 90 Compar. DOP M50 (MPa) 0.05 0.13 0.19 Ex. 6 Tb (MPa) 0.07 0.220.38 Eb (%) 70 90 90 DINA M50 (MPa) 0.05 0.13 0.17 Tb (MPa) 0.07 0.290.36 Eb (%) 70 110 100 TOTM M50 (MPa) 0.06 0.05 0.09 Tb (MPa) 0.11 0.120.15 Eb (%) 100 120 90 Polybutene M50 (MPa) 0.07 0.08 0.13 35H Tb (MPa)0.14 0.22 0.26 Eb (%) 100 120 100 Alkene M50 (MPa) 0.04 0.15 0.21 100PTb (MPa) 0.07 0.28 0.38 Eb (%) 90 100 90 Alkene M50 (MPa) 0.05 0.12 0.18200P Tb (MPa) 0.15 0.28 0.37 Eb (%) 140 130 100 Ref. Blank M50 (MPa)0.16 0.15 0.18 Tb (MPa) 0.26 0.29 0.41 Eb (%) 90 100 110

Example 11

Some specimens of the cured sheet prepared in Example 9 (dumbbellspecimens) were set in a sunshine weather-o-meter (product of SugaTesting Instruments, Model WEL-SUN-DC, black panel temperature 63° C.,rainfall time 18 min./irradiation time 2 hrs). After a predeterminedtime period, the specimens were taken out and subjected to tensiletesting in the same manner as in Example 9. The results are shown inTable 7.

Comparative Example 7

Some specimens of the cured sheet prepared in Comparative Example 5(dumbbell specimens) were set in a sunshine weather-o-meter (product ofSuga Testing Instruments, Model WEL-SUN-DC, black panel temperature 63°C., rainfall time 18 min./irradiation time 2 hrs). After a predeterminedtime period, the specimens were taken out and subjected to tensiletesting in the same manner as in Example 11. The results are shown inTable 7.

TABLE 7 Effect of high molecular plasticizer (D) on weather resistance(tensile properties) Plasticizer Initial After 500 h Ex. 11 Polymer [16]M50 (MPa) 0.05 0.05  Tb (MPa) 0.14 0.15  Eb (%) 180 170 PN-280 M50 (MPa)0.07 0.08  Tb (MPa) 0.15 0.15  Eb (%) 100 90 Compar. Ex. 7 DOP M50 (MPa)0.05 0.07  Tb (MPa) 0.07 0.08  Eb (%) 70 60 DINA M50 (MPa) 0.05 —  Tb(MPa) 0.07 0.05  Eb (%) 70 40 TOTM M50 (MPa) 0.06 —  Tb (MPa) 0.11 0.04 Eb (%) 100 30 Polybutene 35H M50 (MPa) 0.07 0.08  Tb (MPa) 0.14 0.14 Eb (%) 100 80 Alkene 100P M50 (MPa) 0.04 0.06  Tb (MPa) 0.07 0.09  Eb(%) 90 80 Alkene 200P M50 (MPa) 0.05 —  Tb (MPa) 0.15 0.05  Eb (%) 14020 Ref. Blank M50 (MPa) 0.16 0.16  Tb (MPa) 0.26 0.27  Eb (%) 90 90

Example 12

Some specimens of the cured sheet prepared in Example 9 (dumbbellspecimens) were coated with various alkyd coatings and left standingindoors. After a predetermined period of time, the coated surface wastouched with a finger to assess the degree of curing. The results areshown in FIG. 8.

Comparative Example 8

Some specimens of the cured sheet prepared in Comparative Example 5(dumbbell specimens) were coated with various alkyd coatings and leftstanding indoors. After a predetermined period of time, the coatedsurface was touched with a finger to assess the degree of curing in thesame manner as in Example 12. The results are shown in FIG. 8.

TABLE 8 Effect of high molecular plasticizer (D) on alkyd coatingcoatability Plasticizer Ex. 12 Compar. Ex. 8 Polymer Polybutene Coating[16] PN-280 35H DOP DOA Schakelverf ◯/◯ ◯/◯ ◯/◯ X/X X/Δ Rubbol AZ Δ/◯ΔΔ/Δ X/Δ X/X X/Δ Sigmasolid Δ/◯Δ Δ/Δ ◯Δ/◯ X/X X/X semigloss Table 8 showsthe evaluation after 1 day/the evaluation after 7 days ◯: Completelycured Δ: Tacky X: Uncured The alkyd coatings used are: Schakelverf:Product of Sigma Rubbol AZ: Product of Akzo Sigmasolid semigloss:Product of Sigma

EXAMPLES RELATING TO THE FOURTH ASPECT OF THE INVENTION ProductionExample 6

A 10-L separable flask equipped with a reflux-condenser and a stirrerwas charged with CuBr (42.0 g, 0.293 mol). After nitrogen gas purging,acetonitrile (559 mL) was added and the mixture was stirred on an oilbath at 70° C. for 45 minutes. Thereafter, butyl acrylate (1.00 kg),diethyl 2,5-dibromoadipate (176 g, 0.488 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (2.00 mL, 1.66 g, 9.58 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(4.00 kg) was continuously added dropwise over 190 minutes. In thecourse of dripping butyl acrylate, triamine (6.00 mL, 4.98 g, 288 mmol)was further added. At 310 minutes after initiation of the reaction,1,7-octadiene (1.44 L, 1.07 kg, 9.75 mol) and triamine (20.5 mL, 17.0 g,98.1 mmol) were added, and the whole mixture was stirred under heatingat 70° C. for 210 minutes.

This reaction mixture was diluted with hexane and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [17]) was obtained. This polymer [17] had a number averagemolecular weight of 14000 and a molecular weight distribution value of1.3.

A 10-L separable flask equipped with a condenser was charged withpolymer [17] (2.7 kg), potassium benzoate (142 g) andN,N-dimethylacetamide (2.7 L) and the mixture was stirred under nitrogenat 70° C. for 25 hours. The N,N-dimethylacetamide was distilled offunder reduced pressure and the residue was diluted with toluene andtreated with an activated alumina column to remove the toluene-insolublematter (KBr and excess potassium benzoate). The volatile fraction of thefiltrate was then distilled off under reduced pressure to give polymer[18].

A 2-L round-bottom flask equipped with a condenser was charged withpolymer [18] (2.7 kg), aluminum silicate (540 g, product of KyowaChemical, Kyowaad 700 PEL) and toluene (2.7 L) and the mixture wasstirred under nitrogen at 100° C. for 5 hours. The aluminum silicate wasthen filtered off and the toluene in the filtrate was distilled offunder reduced pressure to give polymer [19].

A 1-L pressure-resisting reaction vessel was charged with polymer [19](409 g), dimethoxymethylhydrosilane (27.0 mL, 0.22 mol), methylorthoformate (8.0 mL, 0.07 mmol) and Cplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was 10-3 molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 1 hour. The volatile fraction of the mixture wasthen distilled off under reduced pressure to give a silyl-terminatedpolymer (polymer [20]). This polymer had a number average molecularweight (GPC method, polystyrene equivalent) of 13900 and a molecularweight distribution value of 1.4. The average number of silyl groupsintroduced per mole of the polymer was 1.5 as determined by ¹H NMRanalysis.

Production Example 7 Example of Synthesis of a Br Group-TerminatedPoly(butyl acrylate)

A 2-L separable flask equipped with a reflux-condenser and a stirrer wascharged with CuBr (5.54 g, 38.6 mmol). After nitrogen gas purging,acetonitrile (73.8 mL) was added and the mixture was stirred on an oilbath at 70° C. for 30 minutes. Thereafter, butyl acrylate (132 g),methyl 2-bromopropionate (14.4 mL, 0.129 mol) andpentamethyldiethylenetriamine (4.69 mL, 0.022 mol) were added and thereaction was started. Under heating at 70° C. with constant stirring,butyl acrylate (528 g) was continuously added dropwise over 90 minutesand the whole mixture was stirred under heating for 80 minutes.

This reaction mixture was diluted with toluene and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby a poly(butyl acrylate) having a Br groupat one molecular chain terminus (polymer [21]) was obtained. Thispolymer [21] had a number average molecular weight of 5800 and amolecular weight distribution value of 1.14.

Production Example 8 Example of Synthesis of a Poly(butyl acrylate)Having an Alkenyl Group at one Molecular Chain Terminus

A 500-mL flask equipped with a condenser was charged with the polymer[21] (150 g) obtained in Production Example 2, potassium pentenoate(8.29 g) and N,N-dimethylacetamide (150 mL) and the mixture was stirredat 70° C. for 6 hours. The N,N-dimethylacetamide was then distilled offand the residue was diluted with toluene and treated with an activatedalumina column. The toluene was then distilled off to give a polymer.

A reaction vessel was charged with the above polymer (20 g), aluminumsilicate (4.0 g, product of Kyowa Chemical, Kyowaad 700 PEL) and toluene(20 mL) and the mixture was stirred under nitrogen at 100° C. for 1hour. The aluminum silicate was then filtered off and the filtrate wasconcentrated to give a poly(butyl acrylate) having an alkenyl group atone molecular chain terminus (polymer [22]). This polymer had a numberaverage molecular weight of 5800 and a molecular weight distributionvalue of 1.13. The viscosity was 11 Pa·s (Type E viscosimeter, 23° C.).

Production Example 9 Example of Synthesis of a Poly(butyl acrylate)Having a Silyl Group at one Molecular Chain Terminus

A 30-mL pressure-resisting reaction vessel was charged with the polymer[22] (9.4 g) obtained in Production Example 7,dimethoxymethylhydrosilane (0.58 mL, 4.7 mmol), methyl orthoformate(0.17 mL, 1.6 mmol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was-10⁻⁴ molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 1 hour. Then, dimethoxymethylhydrosilane (0.58 mL,4.7 mmol) and platinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxanecomplex (2×10⁻⁴ molar equivalents with respect to the alkenyl group ofthe polymer) were further added and the whole mixture was heated at 100°C. for 1 hour. This reaction mixture was concentrated to give apoly(butyl acrylate) having a silyl group at one molecular chainterminus (polymer [23]). This polymer had a number average molecularweight of 6100 and a molecular weight distribution value of 1.18. Theaverage number of silyl groups introduced per mole of the polymer was1.0. The viscosity was 13 Pa·s (Type E viscosimeter, 23° C.)

Example 13

One-hundred parts of the polymer [20] obtained in Production Example 6and 50 parts of polymer [23] as a reactive plasticizer were admixed,followed by addition of 1 part of Sn(IV) catalyst (dibutyltindiacetylacetonate) with stirring, and the whole mixture was degassedunder reduced pressure and molded to give a cured product in the form ofa 2 mm-thick flat sheet. Curing was effected by allowing the sample tostand in an interior environment for 1 day and further at 50 C for oneday. Then, the gel fraction was determined. The viscosity of a mixtureof 100 parts of polymer [20] and 50 parts of polymer [23] was alsomeasured (Type E viscosimeter, 23° C.). The results are shown in-Table9.

Comparative Example 9

Except that a nonreactive plasticizer having no silyl group (polymer[22]) was used in lieu of the reactive plasticizer (polymer [23]) usedin Example 13, a cured product was fabricated and evaluated in the samemanner as in Example 13. The viscosity of a mixture of 100 parts ofpolymer [20] and 50 parts of polymer [22] was also measured [Type Eviscosimeter, 23° C.]. The results are shown in Table 9.

Reference Example 1

Except that the reactive plasticizer (polymer [23]) used in Example 13was omitted from the formulation, a cured product was fabricated andevaluated in the same manner as in Example 13. The viscosity of polymer[20] alone was also measured [Type E viscosimeter, 23° C.]. The resultsare shown in Table 9.

Table 9

Gel Fraction and Composition Viscosity of Cured Product When ReactivePlasticizer (E) is Used

Viscosity Gel fraction (%) (Pa · s) Ex. 13 70 44 Compar. Ex. 9 50 42Ref. Ex. 1 80 67

Example 14

A cured product was fabricated in the same manner as in Example 13,except that curing was effected by allowing the sample to stand in aninterior environment for 2 days and further 10 at 50° C. for 3 days.From the cured product in the form of a sheet, a No. 2 (⅓) dumbbelltestpiece was punched out and subjected to tensile testing with ShimadzuCorporation's autograph (measuring conditions: 23° C., 200 mm/min). Theresults are shown in Table 10.

Comparative Example 10

A cured product was fabricated in the same manner as in ComparativeExample 9, except that curing was effected in the same manner as inExample 14 and the cured product was subjected to tensile testing as inExample 14. The results are shown in Table 10.

TABLE 10 Tensile characteristics of the cured product when reactiveplasticizer (E) is used M50 M100 Tmax (MPa) (MPa) (MPa) Eb (%) Ex. 140.017 0.031 0.108 280 Compar. Ex. 9 0.038 0.071 0.103 150

EXAMPLES RELATING TO THE FIFTH ASPECT OF THE INVENTION ProductionExample 10

A 10-L separable flask equipped with a reflux-condenser and a stirrerwas charged with CuBr (28.0 g, 0.195 mol). After nitrogen gas purging,acetonitrile (559 mL) was added and the mixture was stirred on an oilbath at 70° C. for 15 minutes. Thereafter, butyl acrylate (1.00 kg),diethyl 2,5-dibromoadipate (117 g, 0.325 mol) andpentamethyldiethylenetriamine [hereinafter referred to briefly astriamine] (1.70 mL, 1.41 g, 8.14 mmol) were added and the reaction wasstarted. Under heating at 70° C. with constant stirring, butyl acrylate(4.00 kg) was continuously added dropwise over 175 minutes. In thecourse of dripping butyl acrylate, triamine (8.50 mL, 7.06 g, 40.7 mmol)was further added. At 370 minutes after initiation of the reaction,1,7-octadiene (1.57 L, 1.17 kg, 7.10 mol) and triamine (20.4 mL, 16.9 g,97.7 mmol) were added, and the whole mixture was stirred under heatingat 70° C. for 220 minutes.

This reaction mixture was diluted with hexane and passed through anactivated alumina column, and the volatile matter was distilled offunder reduced pressure, whereby an alkenyl group-terminated polymer(polymer [24]) was obtained. This polymer [24] had a number averagemolecular weight of 21300 and a molecular weight distribution value of1.3.

A 2-L separable flask equipped with a condenser was charged with polymer[24] (0.73 kg), potassium benzoate (25 g) and N,N-dimethylacetamide (0.7L) and the mixture was stirred under nitrogen at 70° C. for 12 hours.The N,N-dimethylacetamide was then distilled off under reduced pressureand the residue was diluted with toluene and treated with an activatedalumina column to remove the toluene-insoluble matter (KBr and excesspotassium benzoate). The volatile fraction of the filtrate was thendistilled off under reduced pressure to give polymer [25].

A 2-L round-bottom flask equipped with a condenser was charged withpolymer [25] (0.73 kg), aluminum silicate (150 g, product of KyowaChemical, Kyowaad 700 PEL) and toluene (4.0 L) and the mixture wasstirred under nitrogen at 100° C. for 5 hours. The aluminum silicate wasthen filtered off and the toluene in the filtrate was distilled offunder reduced pressure to give polymer [26].

A 1-L pressure-resisting reaction vessel was charged with polymer [26](390 g), dimethoxymethylhydrosilane (36.0 mL, 0.292 mol), methylorthoformate (7.10 mL, 0.065 mol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was 10-2 molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 400 minutes. The volatile fraction of the mixturewas then distilled off under reduced pressure to give a silyl-terminatedpolymer (polymer [27]). This polymer had a number average molecularweight (GPC method, polystyrene equivalent) of 246000 and a molecularweight distribution value of 1.5. The average number of silyl groupsintroduced per mole of the polymer was 3.0 as determined by ¹H NMRanalysis.

Production Example 11

A 1-L pressure-resisting reaction vessel was charged with the polymer[26] (300 g) obtained in Production Example 10,dimethoxymethylhydrosilane (18.0 mL, 0.146 mol), methyl orthoformate(4.97 mL, 0.045 mol) andplatinum(0)-1,1,3,3-tetramethyl-1,3-divinyldisiloxane complex. Theamount of use of the platinum catalyst was 10-2 molar equivalents withrespect to the alkenyl group of the polymer. This reaction mixture washeated at 100° C. for 250 minutes. The volatile fraction of the mixturewas then distilled off under reduced pressure to give a silyl-terminatedpolymer (polymer [28]). This polymer had a number average molecularweight (GPC method, polystyrene equivalent) of 246000 and a molecularweight distribution value of 1.5. The average number of silyl groupsintroduced per mole of the polymer was 1.2 as determined by ¹H NMRanalysis.

Example 15

One-hundred parts of the polymer [27] obtained in Production Example 10was mixed with 1 part of silanol-containing compound (CH₃)₃SiOC₆H₅,followed by addition of 4 parts of a mixture of Sn(II) catalyst(stannous dioctanoate) and laurylamine (mixing ratio=3:1). Afterstirring and vacuum degassing, a 2 mm-thick cured sheet was fabricated.Curing was effected by allowing the sample to stand in an interiorenvironment for 2 days and further at 50° C. for 3 days. From the curedproduct in the form of a sheet, a No. 2 (⅓) dumbbell testpiece waspunched out and subjected to tensile testing with Shimadzu Corporation'sautograph (measuring conditions: 23° C., 200 mm/min). The results areshown in Table 11.

Example 16

Except that 1 part of (—CH₃)₃SiO[CH₂CH(CH₃)O]₇SiMe₃ was used in lieu of1 part of the silanol-containing compound (CH₃)₃SiOC₆H₅ used in Example15, a cured product was prepared and subjected to tensile testing in thesame manner as in Example 15. The results are shown in Table 11.

Example 17

Except that 1 part of C₁₂H₂₅OSiMe₃ was used in lieu of 1 part of thesilanol-containing compound (CH₃)₃SiOC₆H₅ used in Example 15, a curedproduct was prepared and subjected to tensile testing in the same manneras in Example 15. The results are shown in Table 11.

Example 18

Except that 1 part of C₄H₉OSiMe₃ was used in lieu of 1 part of thesilanol-containing compound (CH₃)₃SiOC₆H₅ used in Example 15, a curedproduct was prepared and subjected to tensile testing in the same manneras in Example 15. The results are shown in Table 11.

Comparative Example 11

Except that the silanol-containing compound used in Example 15 wasomitted, a cured product was prepared and subjected to tensile testingin the same manner as in Example 15. The results are shown in Table 11.

Comparative Example 12

Except that the polymer [28] obtained in Production Example 11 wasemployed, a cured product was fabricated and subjected to tensiletesting in the same manner as in Comparative Example 11. The results areshown in Table 11.

In all the above examples and comparative examples, the surfacecondition of the cured product was examined by finger touch and thesurface tackiness (residual tack) was evaluated. The results are shownin Table 11.

TABLE 11 Tensile characteristics and surface condition of the curedproduct when silanol-containing compound (F) is used Addition amount (inM50 M100 Tmax Eb Residual parts) (MPa) (MPa) (MPa) (%) tack Ex. 15 1.00.043 0.074 0.23 280 ◯ Ex. 16 1.0 0.035 0.058 0.16 260 ◯ Ex. 17 1.00.058 0.10 0.29 260 ◯ Ex. 18 1.0 0.065 0.11 0.29 230 ◯ Compar. Ex. 00.11 0.20 0.32 150 ◯ 11 Compar. Ex. 0 0.056 0.092 0.13 140 X 12 In Table1, Residual tack: Not tacky ← ◯ > Δ > X → Tacky

INDUSTRIAL APPLICABILITY

The curable composition according to the first aspect of the presentinvention, as constituted as above, reduces the surface tackiness(residual tack) of a cured product obtainable by using a vinyl polymerhaving a crosslinking silyl group as the curable component.

The curable composition according to the second aspect of the invention,the constitution of which has been described above, provides for areduced surface tackiness (residual tack) hence a reduced propensity topick up dust, and an improved alkyd-coating coatability of a curedproduct obtainable by using a vinyl polymer having a crosslinking silylgroup as the curable component with satisfactory mechanical propertiesbeing well sustained.

The curable composition according to the third aspect of the invention,also described above, imparts long-term heat resistance and weatheringresistance to a cured product obtainable with a vinyl polymer having acrosslinking functional group and facilitates coating of the curedproduct with an alkyd coating.

The curable composition according to the fourth aspect of the invention,the constitution of which has been described above, not only contributesto improved workability due to reductions in viscosity in formulationand application stages but also imparts flexibility to the cured productand minimizes adverse influences due to plasticizer migration.

The curable composition according to the fifth aspect of the invention,also described above, is of low viscosity and, yet, gives a flexiblecured product having a high gel fraction, a reduced surface tack, a lowmodulus, and a high elongation.

1. A curable composition comprising the following two components: (A3) avinyl polymer having at least one crosslinking functional group on theaverage per molecule and (D) a high molecular plasticizer having anumber average molecular weight of 500 or over.
 2. The curablecomposition according to claim 1 wherein the vinyl polymer (A3) is amolecular weight distribution value of less than 1.8.
 3. The curablecomposition according to claim 1 wherein the vinyl polymer (A3) is a(meth)acrylic polymer.
 4. The curable composition according to claim 1wherein the vinyl polymer (A3) is an acrylic polymer.
 5. The curablecomposition of any of claim 1 wherein the crosslinking functional groupof the vinyl polymer (A3) is a crosslinking silyl group.
 6. The curablecomposition according to claim 1 wherein the crosslinking functionalgroup of the vinyl polymer (A3) is an alkenyl group.
 7. The curablecomposition according to claim 1 wherein the crosslinking functionalgroup of the vinyl polymer (A3) is a hydroxyl group.
 8. The curablecomposition according to claim 1 wherein the crosslinking functionalgroup of the vinyl polymer (A3) is an amino group.
 9. The curablecomposition according to claim 1 wherein the crosslinking functionalgroup of the vinyl polymer (A3) has a polymerizable carbon-carbon doublebond.
 10. The curable composition according to claim 1 wherein thecrosslinking functional group of the vinyl polymer (A3) is an epoxygroup.
 11. The curable composition according to claim 1 wherein thevinyl polymer (A3) has a main chain produced by living radicalpolymerization technique.
 12. The curable composition according to claim11 wherein the vinyl polymer (A3) has a main chain produced by atomtransfer radical polymerization technique.
 13. The curable compositionaccording to claim 12 wherein the atom transfer radical polymerizationtechnique is carried out by using, as the catalyst, a transition metalcomplex whose center metal belongs to group 7, 8, 9, 10 or 11 of theperiodic table of the elements.
 14. The curable composition according toclaim 13 wherein the transition metal complex is a complex of copper,nickel, ruthenium or iron.
 15. The curable composition according toclaim 14 wherein the transition metal complex is a complex of copper.16. The curable composition according to claim 1 wherein the highmolecular plasticizer (D) has a number average molecular weight of 500to
 15000. 17. The curable composition according to claim 16 wherein thehigh molecular plasticizer (D) has a number average molecular weight of800 to
 10000. 18. The curable composition according to claim 17 whereinthe high molecular plasticier (D) has a number average molecular weightof 1000 to
 8000. 19. The curable composition according to claim 1wherein the high molecular plasticizer (D) is a vinyl polymer.
 20. Thecurable composition according to claim 19 wherein the high molecularplasticizer (D) has a molecular weight distribution value of less than1.8.
 21. The curable composition according to claim 19 wherein the highmolecular plasticizer (D) is a (meth)acrylic polymer.
 22. The curablecomposition according to claim 20 wherein the high molecular plasticizer(D) is an acrylic polymer.
 23. The curable composition according toclaim 20 wherein the high molecular plasticizer (D) is produced byliving radical polymerization technique.
 24. The curable compositionaccording to claim 23 wherein the high molecular plasticizer (D) isproduced by atom transfer radical polymerization technique.
 25. Thecurable composition according to claim 1 wherein the addition amount ofthe high molecular plasticizer (D) is 5 to 150 weight parts based on 100weight parts of the vinyl polymer (A3) having at least one crosslinkingfunctional group.